Dealt vs Delt Which Spelling Is Correct 2026 Guide

If you’ve ever written dealt vs delt and stopped to wonder which spelling is correct, you’re dealing with a very common irregular verb problem. The confusion makes sense because the two forms sound almost identical in everyday American English. When someone says dealt aloud, you hear something close to delt, so it can feel natural to spell the word exactly as it sounds.

The correct spelling for the past tense and past participle of deal is dealt. The spelling delt is not the standard modern spelling of that verb form. Major dictionaries identify dealt as the past tense and past participle of deal. Cambridge gives the pronunciation as /delt/, which explains why the spelling can feel misleading. (Cambridge Dictionary)

There is an interesting historical detail, though. Older forms of English did use delt as a historical form of the verb. The Oxford English Dictionary record shows delt among earlier forms before dealt became the established modern spelling. (First Circuit Court)

This article explains the difference clearly. You’ll learn the correct spelling, grammar rules, pronunciation, history, sentence patterns, common mistakes, regional usage, and practical editing strategies.

Quick Answer

Dealt is the correct modern English spelling. It is the past tense and past participle of deal. Delt is not standard modern English when you mean the past form of deal. Although historical records contain delt as an older form, modern writers should use dealt in school, business, academic, and everyday writing. (Cambridge Dictionary)

Dealt vs Delt At a Glance Comparison

Feature	Dealt	Delt
Correct modern spelling	Yes	No for the past form of deal
Meaning	Past tense and past participle of deal	Not the standard modern past form of deal
Part of speech	Verb form	Can be a noun in a different meaning
Word type	Irregular verb form	Separate informal noun in dictionary use
Pronunciation	/delt/	/delt/ when referring to the verb incorrectly
Origin	Historical form of deal	Historical variant of dealt in older English
Grammar role	Simple past and past participle	Not used as the modern past form of deal
Formality	Standard	Incorrect for standard modern verb usage
Frequency	Common	Rare in the intended verb sense
Typical contexts	Handled something, distributed something, experienced something, negotiated something	Usually a spelling error when intended as the past of deal
Example	She dealt with the problem quickly.	She dealt with the problem quickly.

There is one important wrinkle. Delt is not completely absent from English dictionaries. Collins records delt as an informal noun meaning the deltoid muscle. That is a completely different word and has nothing to do with the past tense of deal. (Collins Dictionary)

So if you’re writing I delt with it yesterday, the correct form is I dealt with it yesterday.

Dealt vs Delt Which Word Should You Use

Use dealt whenever you’re using the past tense or past participle of deal.

Correct:

I dealt with the complaint yesterday.

She dealt the cards to everyone.

We dealt with the problem quickly.

The company had dealt with similar issues before.

Incorrect in standard modern English:

I delt with the complaint yesterday.

She delt the cards to everyone.

We delt with the problem quickly.

The reason is grammatical rather than stylistic. Deal is an irregular verb. Its main forms are:

Verb form	Word
Base form	deal
Third person singular	deals
Present participle	dealing
Simple past	dealt
Past participle	dealt

Cambridge and Oxford both identify dealt as the past tense and past participle of deal. (Cambridge Dictionary)

Is Delt Ever Acceptable

As the past form of deal, no. Modern standard English uses dealt.

However, delt can appear as a separate informal noun. Collins defines it as an informal term for the deltoid muscle. (Collins Dictionary)

For example:

He worked hard to build his delts.

That use has nothing to do with the verb deal.

There is also a historical reason you may encounter delt in older texts. The Oxford English Dictionary records it among historical forms of the past tense and past participle of deal. (First Circuit Court)

That distinction matters for editors. You shouldn’t describe delt as a meaningless string of letters. It has had real uses. It simply isn’t the correct modern spelling of the verb form most readers intend today.

Why Do Writers Confuse Them

The main reason is pronunciation.

Dealt is pronounced /delt/. (Cambridge Dictionary)

That pronunciation makes the missing a almost invisible in speech. Someone learning English may hear delt and naturally assume that the spelling is delt.

There is also a pattern problem. English contains many verbs whose past forms change in ways that aren’t easy to predict.

For example:

• feel becomes felt.
• keep becomes kept.
• sleep becomes slept.
• leave becomes left.
• mean becomes meant.
• deal becomes dealt.

A learner who knows feel becomes felt might reasonably wonder why deal doesn’t become delt.

English simply doesn’t work from one universal past tense formula. Verb history matters.

Understanding Dealt vs Delt

Dealt

Dealt is the simple past and past participle of deal. Collins and Cambridge both identify it this way. (Collins Dictionary)

The verb deal has several important meanings, so dealt can appear in many kinds of sentences.

Dealt Meaning Handled

One of the most common uses appears in the phrase dealt with.

Here it means handled, addressed, managed, or responded to something.

The manager dealt with the complaint.

She dealt with the problem calmly.

We dealt with the issue before it became serious.

Merriam Webster’s usage information connects dealt with with meanings such as treated, handled, responded to, and considered. (Merriam-Webster)

This is probably the most common context for people searching for this spelling.

Dealt Meaning Distributed

Dealt can also mean distributed something.

The classic example involves playing cards.

He dealt the cards.

She dealt five cards to each player.

The historical development of deal includes the sense of distributing something as someone’s share. The card dealing sense appeared later. (Etymology Online)

The same basic idea of distribution remains visible in modern English.

Dealt Meaning Negotiated

The word can also appear when discussing business or transactions.

The company dealt with several suppliers.

The two sides dealt directly with each other.

Depending on the sentence structure, deal can describe business activity, negotiation, or involvement.

Merriam Webster lists dealt as the past form of deal and gives examples involving business transactions and other uses. (Merriam-Webster)

Dealt Meaning Experienced

English also uses dealt in expressions describing something that happened to someone.

For example:

Life dealt him a difficult hand.

This expression comes from the idea of dealing cards. Someone is metaphorically given a hand in a card game. The phrase has become a common way to describe circumstances someone receives without choosing them.

That metaphor is deeply established in English.

Understanding Delt

For most readers, delt is simply the incorrect spelling of dealt when someone is trying to use the past form of deal.

For example:

I delt with the situation.

should be:

I dealt with the situation.

However, there are two details worth knowing.

Delt As A Historical Form

Historical English was less standardized than modern English. Spelling changed considerably over time and writers used different forms of many words.

The Oxford English Dictionary records delt among historical past tense and past participle forms of deal. It also records several other historical spellings before dealt became the standard modern form. (First Circuit Court)

So if you encounter delt in an old document, don’t automatically assume the writer made a mistake.

Historical spelling and modern standard spelling aren’t always the same thing.

Delt As A Modern Noun

Collins lists delt as an informal noun meaning the deltoid muscle. (Collins Dictionary)

For example:

His delts were well developed.

That usage is especially associated with fitness and bodybuilding language.

This is a completely separate word from the spelling mistake discussed in this article.

The easiest rule remains:

If you’re talking about the past of deal, write dealt.

The Biggest Differences Between Dealt vs Delt Explained

The difference between these forms becomes simple once you separate spelling, pronunciation, grammar, and history.

Spelling

The standard spelling is:

deal → dealt

Not:

deal → delt

The a stays in the written form even though it isn’t pronounced as a separate vowel sound.

Meaning

Dealt carries the meaning of the verb deal in the past.

Depending on context, it can mean:

• Handled something.
• Addressed something.
• Distributed something.
• Gave cards to players.
• Negotiated or conducted business.
• Experienced a situation.

Delt does not carry these meanings in standard modern English.

Grammar

Dealt is a verb form.

It can function as:

• The simple past.
• The past participle.

For example:

I dealt with it yesterday.

Here dealt is the simple past.

I have dealt with this before.

Here dealt is the past participle used with have.

That difference is important.

Pronunciation

Both the correct form and the common misspelling are usually imagined as sounding the same.

The standard pronunciation of dealt is /delt/. Cambridge and Oxford both give this pronunciation. (Cambridge Dictionary)

So pronunciation won’t help you remember the spelling.

You’ll need to connect the sound with the written form.

Writing Style

Dealt works in virtually every standard variety of English.

You can use it in:

• Casual conversation.
• School assignments.
• Business writing.
• Academic papers.
• Journalism.
• Fiction.
• Formal reports.
• Professional emails.

Writing delt as the past form of deal will generally look like a spelling error.

Everyday Usage

Native speakers use dealt naturally and frequently.

I’ve dealt with worse.

She dealt with it well.

He dealt the cards.

We dealt with the problem yesterday.

You don’t need a special formal context to use it.

Regional Preferences

There isn’t a major American and British spelling difference here.

American English uses dealt.

British English uses dealt.

Canadian English uses dealt.

Australian English uses dealt.

The pronunciation is also broadly similar, although accents naturally affect individual sounds.

The key distinction is not regional. It’s standard modern spelling versus an incorrect spelling in the intended verb sense.

Dealt vs Delt Why People Confuse These Words

The Pronunciation Trap

This is the biggest reason.

The word is written dealt but pronounced /delt/. (Cambridge Dictionary)

English has many spelling patterns where letters remain visible even though their pronunciation has changed over centuries.

That means spelling from sound alone can be unreliable.

If you’re writing quickly and thinking only about the sound delt, your brain may produce delt.

The Irregular Verb Trap

English learners often expect verbs to behave consistently.

If a verb ends in a particular sound, it can feel logical to form its past tense using the same spelling pattern as another verb.

But irregular verbs don’t always cooperate.

Deal belongs to an old family of verbs whose forms developed historically rather than following a simple modern rule.

The Visual Pattern Trap

Consider these forms:

• deal
• dealt
• dealing
• deals

The spelling dealt preserves the connection to the base word.

If you write delt, the visual relationship becomes less obvious.

English spelling often preserves historical connections even when pronunciation doesn’t make them obvious.

Autocorrect

Autocorrect may catch delt in some applications. It may also behave differently depending on the software dictionary.

More importantly, you shouldn’t rely on spell checking alone.

A spelling checker may flag a nonstandard word. A good editor also understands why the word is wrong and can recognize legitimate special uses.

Internet Search Results

Search engines can make the situation confusing because delt does exist as a word in some contexts.

You might search for delt meaning and discover the informal fitness term.

That doesn’t make delt correct in a sentence such as:

I delt with the problem.

The intended verb determines the answer.

Dealt vs Delt Grammar Rules You Should Know

The best way to master this pair is to understand how deal behaves.

The Basic Verb Pattern

Tense or form	Correct form
Present	deal
Third person present	deals
Present participle	dealing
Simple past	dealt
Past participle	dealt

The most important point is that the simple past and past participle are identical.

Simple Past

Use dealt for a completed action in the past.

I dealt with the customer yesterday.

She dealt the cards after everyone sat down.

They dealt with the problem quickly.

Present Perfect

Use dealt after forms of have in the present perfect.

I have dealt with this before.

She has dealt with difficult customers.

They have dealt with similar problems.

Past Perfect

Use dealt after had in the past perfect.

We had dealt with the issue before the meeting.

She had already dealt with the complaint.

Future Perfect

Use dealt after will have.

By Friday, we will have dealt with all the requests.

The important point is that delt never replaces dealt in these standard structures.

Dealt With

One of the most useful phrases to remember is:

dealt with

This usually means handled or addressed.

The teacher dealt with the issue.

The company dealt with the complaint.

We dealt with the problem immediately.

Merriam Webster identifies dealt with as the past form of deal with and gives meanings connected with treating, handling, and addressing something. (Merriam-Webster)

Dealt In

The phrase dealt in has several uses.

One common meaning involves buying and selling something as a business.

They dealt in rare books.

In the past:

They dealt in rare books for decades.

Merriam Webster records deal in as meaning to buy and sell something as a business and also to be involved with something. (Merriam-Webster)

Dealt Out

Dealt out can refer to distributing something.

The teacher dealt out the worksheets.

It can also appear metaphorically.

The policy dealt out harsh consequences.

Dealt A Blow

English often uses dealt in the phrase dealt a blow.

The loss dealt a serious blow to the team.

Cambridge gives dealt a blow as an example of the verb meaning to cause damage to someone’s hopes or position. (Cambridge Dictionary)

This is a useful phrase for formal writing because it appears often in journalism and analytical prose.

Sentence Examples For Dealt vs Delt That Sound Natural

Ten Examples With Dealt

1. I dealt with the customer complaint yesterday.
2. She dealt with the problem before it became serious.
3. The manager dealt with the situation calmly.
4. He dealt the cards to everyone at the table.
5. We dealt with several unexpected issues during the project.
6. The company had dealt with similar cases before.
7. The decision dealt a major blow to the team’s plans.
8. They dealt directly with the supplier.
9. She has dealt with difficult clients for many years.
10. The teacher dealt with the question during class.

Each sentence uses dealt as the correct past form or past participle of deal.

Ten Examples With Delt

There are no standard modern examples where delt should replace dealt as the past tense or past participle of deal.

Instead, here are corrected versions of common mistakes:

1. Incorrect: I delt with the issue.Correct: I dealt with the issue.
2. Incorrect: She delt the cards.Correct: She dealt the cards.
3. Incorrect: We delt with the complaint.Correct: We dealt with the complaint.
4. Incorrect: He delt with everything alone.Correct: He dealt with everything alone.
5. Incorrect: They delt in antiques.Correct: They dealt in antiques.
6. Incorrect: I had delt with this before.Correct: I had dealt with this before.
7. Incorrect: She has delt with many problems.Correct: She has dealt with many problems.
8. Incorrect: The event delt a blow to sales.Correct: The event dealt a blow to sales.
9. Incorrect: He delt the cards quickly.Correct: He dealt the cards quickly.
10. Incorrect: We delt with the matter yesterday.

Correct: We dealt with the matter yesterday.

These corrections reveal the pattern clearly. The spelling stays dealt regardless of the meaning of the verb.

Common Writing Mistakes Of Dealt vs Delt and How to Avoid Them

Mistake One

She delt with the problem.

Correct:

She dealt with the problem.

Mistake Two

He has delt with this issue before.

Correct:

He has dealt with this issue before.

The helping verb has requires the past participle. That form is still dealt.

Mistake Three

We delt the cards.

Correct:

We dealt the cards.

The word remains unchanged.

Mistake Four

The company delt with customer complaints.

Correct:

The company dealt with customer complaints.

This mistake is especially common in fast informal writing.

Mistake Five

Changing the word because it sounds like delt.

This is the central proofreading mistake.

Don’t spell the word according to its sound. Remember the written form:

deal → dealt

Mistake Six

Thinking that every irregular verb follows the same spelling pattern.

English has many historical irregularities.

You can’t reliably create a past tense simply by copying the spelling pattern of another verb.

Mistake Seven

Assuming a dictionary listing makes delt correct in every context.

It doesn’t.

A dictionary can contain a word that belongs to a different vocabulary area.

Collins lists delt as an informal noun for the deltoid muscle. (Collins Dictionary)

That doesn’t make it a valid past form of deal.

Dealt vs Delt Pronunciation Made Simple

Pronunciation is one of the most interesting parts of this spelling problem.

Dealt Pronunciation

The standard pronunciation is:

/delt/

Cambridge lists the American pronunciation of dealt as /delt/. Oxford also gives /delt/. (Cambridge Dictionary)

The sound is close to:

delt

It is one syllable.

The vowel sound is short and similar to the vowel in words such as felt and help for many American speakers.

Syllable Breakdown

dealt

One syllable.

You don’t pronounce the a as a separate sound.

That’s why the spelling can surprise learners.

Stress Pattern

Because dealt has only one syllable, there is no need to choose between multiple stressed syllables.

The entire word carries the natural stress.

Common Pronunciation Mistake

Some learners may try to pronounce every written vowel.

That can produce an unnatural pronunciation.

Don’t say it as two syllables.

The standard form is one syllable:

delt

A Useful Pronunciation Memory Trick

Say the word aloud:

deal

Then say:

dealt

Notice that the vowel changes in pronunciation.

The spelling changes too but the a remains visible in writing.

That written a is the part you need to remember.

Dealt vs Delt Word History and Origin

The history of dealt explains why the spelling may feel less predictable than the pronunciation.

The History Of Deal

Merriam Webster traces the verb deal to Middle English delen and Old English dǣlan, with meanings related to dividing and distributing. It connects the word with related Germanic forms. (Merriam-Webster)

Etymonline gives a similar history and traces the verb through Old English to a Proto Germanic root connected with dividing and distributing. (Etymology Online)

The original idea was essentially about dividing something into portions.

That basic concept helps explain several modern meanings.

If you divide cards among players, you deal them.

If you give someone their share, you deal something out.

For conducting business with someone, you deal with them.

If you handle a problem, you deal with it.

The modern meanings developed over a long period.

Historical Forms

The spelling wasn’t always dealt.

The Oxford English Dictionary record includes historical forms such as delt, dalt, delte, deled, dealte, and other variants. (First Circuit Court)

This is a useful reminder that English spelling has never been completely fixed throughout its history.

The modern standard settled on dealt.

So the modern rule is clear even though the historical record is more complicated.

Why Dealt Won

Modern English spelling gradually became more standardized through printing education dictionaries and wider written communication.

Older spelling variation became less common as conventions became established.

Today readers expect the form dealt.

That’s why a historical variant shouldn’t be treated as a modern alternative simply because it appears in older records.

Dealt vs Delt Usage Across English Speaking Countries

American English

American English uses dealt as the standard past tense and past participle of deal.

I dealt with it yesterday.

Cambridge’s American Dictionary gives dealt as the past tense and past participle and provides the pronunciation /delt/. (Cambridge Dictionary)

British English

British English also uses dealt.

Collins gives the British pronunciation /dɛlt/ and identifies the form as the past tense and past participle of deal. (Collins Dictionary)

There is no modern British spelling preference for delt as the past form.

Canadian English

Canadian English follows the same standard form.

Use dealt in Canadian writing when referring to the past of deal.

Australian English

Australian English also uses dealt.

The core grammar doesn’t change simply because the variety of English changes.

The Important Regional Point

This isn’t like color and colour.

There isn’t a standard American spelling and a standard British spelling here.

The modern form is dealt across major English varieties.

Pronunciation can vary slightly. The spelling does not change.

Dealt vs Delt Real World Usage

Daily Conversation

You’ll hear dealt constantly in ordinary speech.

I dealt with it already.

We’ve dealt with that before.

She dealt with the situation well.

The word is completely natural in casual conversation.

School Writing

Students should use dealt in essays assignments and exams.

The government dealt with the crisis by introducing new rules.

Using delt in a school paper would normally be marked as a spelling error.

Business Communication

Business writing frequently uses phrases such as:

We dealt with the supplier directly.

The issue was dealt with immediately.

Our team has dealt with similar requests.

The form is especially common because deal with is a standard business expression.

Academic Writing

Academic writing often uses dealt with to describe how a text study or researcher addressed a subject.

The study dealt with the effects of sleep deprivation.

The chapter dealt with several competing theories.

Merriam Webster notes that deal with can describe having something as a subject matter. (Merriam-Webster)

Books

Writers use dealt in both literal and figurative contexts.

He dealt the cards slowly.

She had dealt with difficult circumstances before.

The novel dealt with grief and memory.

Journalism

Journalists often use the word when describing events responses and consequences.

Officials dealt with the disruption overnight.

The decision dealt a major blow to the industry.

The word is concise and flexible.

Online Writing

Blogs forums and websites frequently use dealt with.

Here’s how we dealt with the problem.

The guide explains how the issue was dealt with.

Social Media

Casual social media writing uses the same standard spelling.

I’ve dealt with worse.

We dealt with it and moved on.

Even highly informal writing doesn’t normally turn dealt into delt when the writer intends the past of deal.

Dealt vs Delt Similar Words and Frequently Confused Terms

Understanding related forms can strengthen your command of this verb.

Deal

Deal is the base form.

I deal with customer requests.

Use it for present time or after certain helping verbs.

Deals

Deals is the third person singular present form.

She deals with difficult customers every day.

Dealing

Dealing is the present participle and gerund form.

We are dealing with a serious issue.

Dealing with complaints requires patience.

Dealt

Dealt is both the simple past and past participle.

We dealt with the issue yesterday.

We have dealt with the issue already.

Handled

Handled is often a useful synonym for dealt with.

She handled the complaint well.

The words aren’t interchangeable in every sentence but they overlap strongly in the sense of managing a problem.

Addressed

Addressed can replace dealt with in formal writing.

The report addressed the main concerns.

This can be more precise in academic contexts.

Managed

Managed can also overlap with dealt with.

He managed the situation calmly.

Again, context determines the best word.

Distributed

When dealt means gave out or distributed something, distributed can be a clearer alternative.

She distributed the cards.

However, in card games dealt is the natural term.

Professional Editor’s Advice About Dealt vs Delt

A skilled editor treats dealt as a spelling issue only when the context reveals the writer intended the past of deal.

That sounds obvious but it matters.

Suppose you see:

The trainer worked hard to develop his delts.

You shouldn’t change delts to dealt. The sentence is about muscles.

Now suppose you see:

The manager delt with the complaint.

The context clearly points to the verb deal with.

Correct it to:

The manager dealt with the complaint.

This is why proofreading isn’t simply a search for unusual words.

Read For Function

Ask what the word is doing in the sentence.

For describing an action that happened in the past.

Is it part of dealt with.

Is it part of a perfect construction such as has dealt.

If so, the answer is dealt.

Use The Base Verb Test

When you’re unsure, mentally return to the present form.

She delt with the problem.

Ask:

What is the base verb.

Deal.

Now form the past.

Dealt.

This simple technique works well for irregular verbs.

Don’t Invent Past Tenses

English speakers sometimes create forms that feel logical but aren’t standard.

For example:

deal → delt

looks plausible because several English verbs shorten their vowel in the past.

But language isn’t an equation where you can apply one formula to every verb.

Learn the actual form.

Watch For Dealt With

If you see a sentence containing delt with, the correction is almost always immediate:

delt with → dealt with

This phrase is common enough that it should become visually familiar.

Remember The Written Vowel

The strongest memory trick is:

Deal keeps the a in dealt.

You don’t hear that a clearly but you still write it.

Think of the spelling as a visual link between:

deal → dealt

That is more useful than trying to memorize delt as a sound.

Frequently Asked Questions

Is Dealt The Correct Past Tense Of Deal

Yes. Dealt is the correct simple past tense of deal. It is also the past participle. For example, you can say I dealt with the problem yesterday and I have dealt with this before. Cambridge Oxford and Collins all identify dealt as the past tense and past participle of deal. (Cambridge Dictionary)

Is Delt A Correct Spelling Of Dealt

No. Delt is not the standard modern spelling of the past tense or past participle of deal. The correct form is dealt. Historical English did contain delt as a past form, and the Oxford English Dictionary records it among older variants. Modern standard English has settled on dealt. (First Circuit Court)

Why Is Dealt Pronounced Delt

The spelling and pronunciation developed differently over time. Modern dealt is pronounced /delt/, so the written a isn’t heard as a separate vowel sound. Cambridge and Oxford both give /delt/ as the pronunciation. This creates an understandable spelling trap because a person who learns the word mainly through speech may naturally write delt. (Cambridge Dictionary)

How Do You Remember The Spelling Of Dealt

Connect the past form directly to its base verb: deal becomes dealt. Don’t try to spell the word from its pronunciation. The sound is /delt/ but the written form contains a. A useful memory line is deal keeps its a in dealt. This visual connection is especially helpful when you’re proofreading quickly.

Is Delt A Real English Word

Yes but not as the standard past tense of deal. Collins lists delt as an informal noun meaning the deltoid muscle. Historical English sources also record delt as an older form of the verb deal. Those are separate facts. In modern standard writing, use dealt for the past tense and past participle of deal. (Collins Dictionary)

Should I Write Dealt With Or Delt With

Write dealt with. This phrase is the past form of deal with, which commonly means handled addressed or responded to something. For example, She dealt with the complaint quickly is correct. She delt with the complaint quickly is a spelling error in standard modern English. Merriam Webster lists dealt with as the past form of deal with. (Merriam-Webster)

Is Dealt An Irregular Verb

Yes. Dealt is the irregular past form of deal. Instead of forming the past by simply adding ed, English changes the form to dealt. The same form also serves as the past participle. You therefore say I dealt, she dealt, and they dealt, as well as I have dealt and she had dealt.

What Does Dealt With Mean

Dealt with commonly means handled addressed or managed something. For example, The manager dealt with the complaint means the manager handled the complaint. It can also mean that a subject was covered or discussed. For example, The chapter dealt with language change means that language change was one of its subjects. (Merriam-Webster)

Can Dealt Mean Distributed

Yes. Dealt can mean distributed or given out, especially in card games. For example, The dealer dealt five cards to each player means the dealer distributed five cards to each person. The history of deal includes an older meaning connected with giving someone a share and later developed the specific card game sense. (Etymology Online)

Is Dealt Used In American And British English

Yes. Dealt is standard in both American and British English. There is no major regional spelling difference in this form. Pronunciation can vary slightly between accents but the standard written form remains dealt. Cambridge gives /delt/ for its American entry while Collins gives /dɛlt/ in its British entry. (Cambridge Dictionary)

Final Verdict

Dealt is the correct modern spelling for the past tense and past participle of deal.

Use it in sentences such as:

I dealt with the problem.

She dealt the cards.

We have dealt with this issue before.

The decision dealt a serious blow to the project.

Don’t use delt as the past form of deal in standard modern English.

There is a good reason the mistake happens. Dealt is pronounced /delt/, so the spoken form doesn’t reveal the written a. (Cambridge Dictionary)

There is also an interesting historical footnote. Older forms of English included delt among the recorded forms of the verb. That explains why you may occasionally encounter it in historical material. Modern English has standardized the spelling as dealt. (First Circuit Court)

The easiest memory trick is simple:

Deal becomes dealt.

Keep the a in the spelling even though you don’t hear it clearly.

And remember that delt can still appear as a separate informal noun for the deltoid muscle. That meaning has nothing to do with the past tense of deal. (Collins Dictionary)

If you’re writing about handling a problem distributing cards negotiating business or experiencing a difficult situation, dealt is the form you want.