That’s or Thats: Which One Is Correct? A Complete Guide

“That’s” and “thats” look almost identical, but only one form works in standard English. The correct form is “that’s”, with an apostrophe. It is a contraction of “that is” or “that has.”

For example, you can say, “That’s a great idea” to mean “That is a great idea.” You can also say, “That’s been a difficult day” to mean “That has been a difficult day.” The apostrophe shows that letters have been omitted from the original words.

On the other hand, “thats” without an apostrophe is generally considered incorrect in standard written English when you mean “that’s.” People sometimes type it in casual messages because they skip punctuation, but you should avoid it in school, work, formal writing, and published content.

Understanding this small difference can make your writing look much cleaner. The apostrophe may seem like a tiny detail, but it changes the form from a standard contraction into a common spelling error.

If you’ve ever paused while writing “that’s” or “thats,” you’re not alone. The two forms look almost identical, yet one small punctuation mark changes everything.

The correct form in standard English is that’s. The apostrophe matters because it shows that letters have been omitted from a longer expression. In most cases, that’s is a contraction of that is or that has.

By contrast, thats without an apostrophe is generally considered incorrect when you intend to write the contraction. You may see it in quick text messages, social media posts, informal typing, or as a simple typo. However, standard English writing requires the apostrophe.

Understanding the difference becomes much easier once you know what the apostrophe represents. You also need to recognize that that’s has two possible meanings.

Let’s look at the difference clearly and explore when you should use each form.

Reade More:To Fast or Too Fast: Which One Is Correct?

That’s or Thats: Quick Answer

That’s is the correct standard form when you mean “that is” or “that has.”

Thats without an apostrophe is normally incorrect when used as a contraction.

For example:

• That’s my favorite restaurant. = That is my favorite restaurant.
• That’s exactly what I needed. = That is exactly what I needed.
• That’s changed since last year. = That has changed since last year.

The apostrophe in that’s tells the reader that part of the original words has been removed.

Here’s the basic rule:

Use “that’s” when you mean “that is” or “that has.”

If you write “thats” in one of these sentences, you’ve left out the apostrophe.

Form	Standard English?	Meaning	Example
that’s	Yes	that is	That’s a good idea.
that’s	Yes	that has	That’s happened before.
thats	Generally no	Usually intended as that’s	Thats a good idea.

So, if you’re choosing between that’s or thats, choose that’s in normal English writing.

What Does “That’s” Mean?

The word that’s is a contraction. A contraction combines two words and removes one or more letters.

An apostrophe marks the missing letters.

For example:

• do not → don’t
• cannot → can’t
• it is → it’s
• we are → we’re
• that is → that’s

The same principle applies to that’s.

However, that’s can represent two different combinations:

1. That is
2. That has

Context tells you which meaning applies.

“That’s” as a Contraction of “That Is”

The most common use of that’s comes from that is.

For example:

That’s a beautiful house.

You can expand the contraction:

That is a beautiful house.

The meaning remains the same. The contracted version simply sounds more natural in everyday English.

Here are more examples:

• That’s my brother.
• That’s a difficult question.
• That’s the problem.
• That’s very interesting.
• That’s exactly what I meant.
• That’s not what I expected.
• That’s a great opportunity.

In each sentence, you can replace that’s with that is.

“That’s” as a Contraction of “That Has”

The second meaning of that’s comes from that has.

This use usually appears when has works as an auxiliary verb before a past participle.

For example:

That’s changed a lot.

This means:

That has changed a lot.

Other examples include:

• That’s happened before.
• That’s never occurred to me.
• That’s been a problem for years.
• That’s already started.
• That’s become more common recently.

Notice the difference:

That’s a problem.
= That is a problem.

That’s become a problem.
= That has become a problem.

The word following the contraction often gives you a useful clue.

What Does “Thats” Mean?

In ordinary standard English, thats without an apostrophe is generally not the correct spelling when you mean that’s.

For example:

❌ Thats my car.

Correct:

✅ That’s my car.

The problem isn’t pronunciation. Both forms are usually intended to sound the same. The problem is grammatical punctuation.

The apostrophe identifies that’s as a contraction.

You might still encounter thats online. People often omit apostrophes while typing quickly. Others may simply make spelling mistakes.

For casual digital communication, someone might write:

Thats so funny

Most readers will understand the sentence. Nevertheless, standard edited English would write:

That’s so funny.

This distinction matters when you’re writing emails, articles, assignments, business documents, website content, or other polished material.

Why Does “That’s” Need an Apostrophe?

The apostrophe isn’t decorative. It has a grammatical purpose.

When that is becomes that’s, letters disappear.

The apostrophe indicates that omission.

You can think of it as a small sign saying, “Some letters used to be here.”

Compare:

that is → that’s

The apostrophe replaces the omitted part of is.

This same pattern appears throughout English:

Original phrase	Contraction
I am	I’m
You are	You’re
It is	It’s
We are	We’re
They are	They’re
That is	That’s
That has	That’s

This is why writing thats removes an important grammatical signal.

That’s vs. Thats: The Main Difference

The biggest difference is simple: that’s contains an apostrophe, while thats does not.

That small mark tells readers that that’s is a contraction.

Consider these sentences:

That’s the answer.

Thats the answer.

The first sentence follows standard English punctuation. The second omits the apostrophe.

The pronunciation usually won’t help you distinguish them because they sound essentially the same in ordinary speech. You need to recognize the written form.

A Simple Comparison

Feature	That’s	Thats
Apostrophe	Yes	No
Standard contraction	Yes	No
Means “that is”	Yes	No
Means “that has”	Yes	No
Appropriate in polished writing	Yes	No
Common as a typo	No	Yes

If you’re writing professionally, academically, or for publication, that’s is the form to use.

When Should You Use “That’s”?

You should use that’s whenever it correctly represents that is or that has.

Use “That’s” for “That Is”

Use that’s when describing something, identifying something, or making a statement.

For example:

• That’s my seat.
• That’s a strange idea.
• That’s your responsibility.
• That’s the main reason.
• That’s an important point.
• That’s exactly right.

Try expanding the contraction.

That’s my seat.

becomes:

That is my seat.

The sentence still works perfectly.

That replacement test gives you a quick way to check your writing.

Use “That’s” for “That Has”

Use that’s when it means that has.

For example:

• That’s changed considerably.
• That’s happened several times.
• That’s been difficult.
• That’s already been completed.
• That’s become a popular choice.

Try replacing that’s with that has.

That’s been difficult.

becomes:

That has been difficult.

The meaning stays intact.

When Should You Write “That Is” Instead of “That’s”?

Although that’s is completely standard, you don’t always need to use the contraction.

Sometimes writers choose the full form that is for emphasis or formality.

Compare:

That’s the problem.

and:

That is the problem.

Both are grammatically correct.

The second version can place more emphasis on is.

For example:

That is exactly what I wanted to discuss.

The full form can sound more deliberate than:

That’s exactly what I wanted to discuss.

Formal writing can also favor full forms depending on the style guide, publication, institution, or writer’s preference.

However, don’t assume that contractions are automatically unprofessional. Modern professional writing often uses contractions when they fit the intended voice.

The important point is consistency.

That’s vs. “That Is” vs. “That Has”

Understanding the full forms makes that’s or thats much easier.

Form	Full form	Example
That’s	That is	That’s interesting.
That’s	That has	That’s changed.
That is	Full form	That is interesting.
That has	Full form	That has changed.
Thats	—	Generally incorrect as the intended contraction

Consider these two examples:

That’s interesting.

Here, that’s means that is.

That’s changed.

Here, that’s means that has.

The spelling stays exactly the same. Only the meaning changes according to context.

Common Mistakes With That’s and Thats

Many errors involving that’s happen because writers focus on pronunciation instead of grammar.

Mistake: Leaving Out the Apostrophe

Incorrect:

Thats a great idea.

Correct:

That’s a great idea.

The apostrophe belongs between t and s.

Mistake: Treating the Apostrophe as Optional

Some writers believe apostrophes don’t matter in casual writing.

They do matter in standard English.

You might understand:

Thats what I said.

But understanding the sentence doesn’t make its punctuation standard.

Correct:

That’s what I said.

Mistake: Confusing Contractions With Possessives

Apostrophes can show contractions or possession. That’s why they sometimes confuse learners.

In that’s, the apostrophe indicates a contraction.

It does not indicate possession.

This is important because that behaves differently from nouns when expressing possession.

For example:

That’s my phone.

Here, that’s means:

That is my phone.

It does not mean something belongs to “that.”

That’s vs. Its: Why the Apostrophe Can Be Confusing

A useful comparison involves that’s and its.

That’s is a contraction.

Its is normally a possessive determiner.

For example:

That’s a dog.

= That is a dog.

But:

The dog wagged its tail.

Here, its shows possession.

This illustrates an important English rule: an apostrophe doesn’t always mean possession.

In that’s, the apostrophe marks omitted letters.

That’s in Everyday English

You’ll encounter that’s constantly in ordinary communication.

People use it in conversations, messages, emails, social media posts, and many forms of professional writing.

In Conversation

Examples include:

• That’s great!
• That’s okay.
• That’s enough.
• That’s funny.
• That’s true.
• That’s not fair.

These expressions sound natural because contractions are common in spoken English.

In Text Messages

You may see:

That’s awesome!

That’s what I thought.

That’s crazy.

Texting often uses contractions because they make messages shorter and more conversational.

However, shortening a word doesn’t mean removing necessary punctuation.

In Emails

You can use that’s in many emails.

For example:

That’s the document I was looking for.

Or:

That’s a good point. I’ll review the information and respond shortly.

Whether you use that’s or that is depends on your desired tone.

That’s in Formal and Academic Writing

Formal writing sometimes uses fewer contractions.

For example:

That is an important consideration.

may sound more formal than:

That’s an important consideration.

However, the contraction itself isn’t grammatically wrong.

The choice depends on the writing context.

You may prefer the full form when:

• Writing a formal academic paper.
• Following a publication’s style requirements.
• Emphasizing a particular word.
• Maintaining a deliberately formal tone.
• Avoiding contractions throughout a document.

The key is to follow the expectations of your audience.

Is “Thats” Ever Correct?

In standard English, thats is generally not the correct spelling when you intend that’s.

However, you may encounter the sequence thats in unusual contexts.

For example, it could appear as:

• A username.
• A brand or product name.
• A deliberately stylized name.
• A typo.
• Informal writing where the author omitted apostrophes.

These situations don’t change the normal grammatical rule.

If you’re writing a sentence such as:

Thats my answer.

you should write:

That’s my answer.

The same applies to professional content, schoolwork, articles, websites, and edited publications.

How to Remember That’s or Thats

Here’s the easiest memory trick:

If “that is” or “that has” fits, use “that’s.”

For example:

That’s my problem.

Ask:

Can I say That is my problem?

Yes.

Therefore:

✅ That’s my problem.

Now consider:

That’s happened before.

Can you say:

That has happened before?

Yes.

Therefore:

✅ That’s happened before.

If you’re tempted to write thats, stop and perform this quick test.

The Replacement Test

Replace that’s with that is or that has.

If the sentence still makes sense, the apostrophe belongs there.

For example:

That’s a nice car.

→ That is a nice car.

Correct.

That’s been difficult.

→ That has been difficult.

Correct.

This test takes only a second, yet it catches many common errors.

That’s or Thats: Correct Sentence Examples

Let’s look at several examples in context.

Correct Examples

• That’s my favorite book.
• That’s a difficult decision.
• That’s exactly what happened.
• That’s not the answer.
• That’s an interesting question.
• That’s what I wanted to explain.
• That’s already happened once.
• That’s been a common problem.
• That’s changed considerably.
• That’s the reason I called.

Each sentence uses the standard spelling that’s.

Incorrect Examples

These examples incorrectly omit the apostrophe:

• ❌ Thats my favorite book.
• ❌ Thats a difficult decision.
• ❌ Thats exactly what happened.
• ❌ Thats not the answer.
• ❌ Thats an interesting question.

Correct them by adding the apostrophe:

• ✅ That’s my favorite book.
• ✅ That’s a difficult decision.
• ✅ That’s exactly what happened.
• ✅ That’s not the answer.
• ✅ That’s an interesting question.

Case Study: Checking “That’s” in Real Sentences

Imagine you’re proofreading an email that says:

Thats the report we discussed yesterday. Thats been updated with the latest figures.

At first glance, the problem may seem minor.

But both occurrences need correction.

The first thats means that is:

That’s the report we discussed yesterday.

The second thats means that has:

That’s been updated with the latest figures.

The corrected version becomes:

That’s the report we discussed yesterday. That’s been updated with the latest figures.

This example demonstrates why understanding the full forms matters. You aren’t simply memorizing an apostrophe. You’re recognizing what the contraction represents.

That’s vs. Similar Contractions

The same idea appears in several common English contractions.

Contraction	Full form	Example
that’s	that is / that has	That’s correct.
it’s	it is / it has	It’s ready.
what’s	what is / what has	What’s happening?
who’s	who is / who has	Who’s calling?
there’s	there is / there has	There’s a problem.
here’s	here is / here has	Here’s your book.

This pattern can help you recognize why that’s needs an apostrophe.

The apostrophe signals that the form is a contraction.

That’s in Questions and Expressions

That’s often appears in short expressions that native speakers use every day.

Examples include:

• That’s what I mean.
• That’s why I asked.
• That’s how it works.
• That’s where we started.
• That’s when I realized it.
• That’s all I know.
• That’s enough.
• That’s okay.

These structures appear in both casual conversation and ordinary writing.

You may also see related expressions such as:

What’s that?

Here, what’s means what is.

That’s mine.

Here, that’s means that is.

The apostrophe follows the same contraction principle.

Can “That’s” Start a Sentence?

Yes. That’s can naturally begin a sentence.

For example:

That’s the main issue.

That’s why we need another plan.

That’s exactly what I expected.

There is nothing grammatically wrong with starting a sentence with that’s.

The contraction works just like it does elsewhere in a sentence.

Can “That’s” Be Used in Professional Writing?

Yes.

Professional writing doesn’t automatically require every contraction to be expanded.

For example:

That’s an important point to consider.

This can work perfectly well in a professional email or business article.

However, some organizations prefer a more formal style:

That is an important point to consider.

Neither choice is inherently wrong. Your audience and style guide should determine the tone.

What you should avoid is the nonstandard spelling:

❌ Thats an important point to consider.

A Practical Editing Checklist

Before publishing or submitting your writing, check every occurrence of thats.

Ask yourself:

• Does thats mean that is?
• Does thats mean that has?
• If yes, change it to that’s.
• Is the word part of a proper name or unusual label?
• If not, the apostrophe probably belongs there.

This quick checklist works particularly well during proofreading.

Quick Comparison: That’s or Thats

Question	That’s	Thats
Is it standard English?	Yes	Generally no
Is it a contraction?	Yes	No
Can it mean “that is”?	Yes	No
Can it mean “that has”?	Yes	No
Does it need an apostrophe?	Yes	—
Common in polished writing?	Yes	No
Often caused by a typing error?	No	Yes

The answer is straightforward: that’s is the standard choice.

FAQS

Is “thats” a correct word?

Thats is generally not correct when you intend the contraction that’s. Standard English uses the apostrophe in that’s.

Is “that’s” short for “that is”?

Yes. That’s commonly represents that is.

For example:

That’s my house.

means:

That is my house.

Can “that’s” mean “that has”?

Yes. That’s can also represent that has.

For example:

That’s happened before.

means:

That has happened before.

Should I write “that’s” or “thats”?

Use that’s in standard English writing. The apostrophe is necessary when the word functions as the contraction of that is or that has.

Is “thats” acceptable in texting?

People sometimes omit apostrophes in quick messages, so thats may appear in informal texting. However, that’s remains the standard spelling.

Is “that’s” appropriate in formal writing?

Yes. That’s is grammatically correct. Some formal styles prefer fewer contractions, though, so that is may be more suitable in certain contexts.

Why does “that’s” have an apostrophe?

The apostrophe shows that letters have been omitted from that is or that has.

What is the difference between “that’s” and “that is”?

They have the same basic meaning when that’s represents that is. The main difference is tone. That’s sounds more conversational, while that is can sound more formal or emphatic.

Is “thats” a spelling mistake?

Usually, yes, when the writer intends that’s. The missing apostrophe creates a nonstandard form.

How can I quickly check whether “that’s” is correct?

Replace that’s with that is or that has. If one of those full forms works, that’s is appropriate.

Conclusion

The difference between “that’s” and “thats” is simple: “that’s” is the correct standard form, while “thats” is usually an incorrect form when you mean “that is” or “that has.” Use the apostrophe whenever you shorten either phrase.

A quick trick can help you remember. If you can replace “that’s” with “that is” or “that has” and the sentence still makes sense, “that’s” is the right choice. For example, “That’s my book” becomes “That is my book.”