Thank you is the standard form when you are expressing gratitude, and it is normally written as two words. Thankyou is also a recognized noun in some dictionaries, particularly in British English, but it is not the form you should use when simply thanking someone. The hyphenated thank-you is commonly used as a noun or modifier, especially in expressions such as thank-you note or thank-you gift.
So, if you are writing a message such as “Thank you for your help,” use the two-word form. Understanding the difference becomes easy once you know how each form functions in a sentence.
Thank You or Thankyou: Which One Is Correct?
When you want to express gratitude directly to someone, thank you is the standard choice.
Correct
Thank you for your help.
Also seen in dictionary usage, but different in function
She gave me a thankyou for helping her.
Common compound form
She sent me a thank-you note.
Cambridge defines thank you as an expression used to show gratitude, while Collins also recognizes thankyou as a noun.
Therefore, the simple rule is:
Use “thank you” when you are thanking someone.
What Does Thank You Mean?
Thank you is an expression used to show gratitude, appreciation, or politeness.
You can use it after someone gives you something, helps you, compliments you, or does something kind for you.
For example:
Thank you for helping me.
Thank you for the gift.
Thank you for your time.
Thank you so much.
Thank you for coming.
It can also be used when accepting or politely refusing an offer:
Yes, thank you.
No, thank you.
Cambridge lists these as standard uses of thank you, including expressing gratitude and politely accepting or refusing something.
Why Is Thank You Written as Two Words?
The expression thank you comes from the verb thank and the pronoun you.
In a sentence such as:
I thank you for your support.
Thank is the verb and you is the object.
The shorter expression thank you developed from this phrase and became a conventional expression of gratitude.
That is why the normal expression remains:
Thank you
rather than:
Thankyou
The fact that the phrase is often pronounced quickly does not change its standard spelling.
Is Thankyou Ever Correct?
Yes, but this is where the distinction matters.
Thankyou can function as a noun meaning something given or said to express gratitude. Collins lists thankyou as a countable noun and gives thank-you as an alternative form.
For example:
The gift was a thankyou for all her hard work.
However, this usage is less familiar to many American English readers. In polished American writing, thank-you is often the clearer choice when the expression functions as a noun.
For example:
The gift was a thank-you for all her hard work.
So, if your question is whether you should write thankyou instead of thank you when directly thanking someone, the answer is no.
Write:
Thank you for your help.
Not:
Thankyou for your help.
Thank You vs Thank-You
The difference between thank you and thank-you is mainly grammatical.
Thank you
Use thank you as the ordinary expression of gratitude.
Thank you for your kindness.
Thank you for your email.
Thank you so much.
Thank-you
Use thank-you as a noun or modifier in certain constructions.
I wrote a thank-you note.
She sent a thank-you card.
He gave me a thank-you gift.
Merriam-Webster lists thank-you as a noun meaning a polite expression of gratitude, and Cambridge also uses thank-you in compounds such as thank-you note.
Thank You vs Thankyou vs Thank-You
Here is the easiest comparison:
| Form | Main use | Example |
|---|---|---|
| thank you | Direct expression of gratitude | Thank you for your help. |
| thank-you | Noun or compound modifier | I wrote a thank-you note. |
| thankyou | Noun in some dictionary usage | The gift was a thankyou. |
For everyday writing, thank you is the form you will use most often.
Thank You in American English
In American English, thank you is the standard expression used to show appreciation.
For example:
Thank you for calling.
Thank you for your support.
Thank you very much.
American dictionaries also recognize thank-you as a noun. Collins, for example, lists thank-you in American English as a noun meaning an expression of thanks.
The important point is that American English does not normally combine the words into thankyou when the phrase is being used as an ordinary expression of gratitude.
Thank You in British English
British English also commonly uses thank you as the normal expression of gratitude.
However, British dictionary entries give thankyou as an alternative noun form. Collins lists thank you or thankyou as a British English exclamation and noun.
For example:
Thank you for your help.
This remains the natural way to directly thank someone.
The noun form can appear differently:
She gave him a thankyou for his kindness.
In formal or international writing, however, thank-you is often a clearer choice when you need the noun form.
Common Examples of Thank You
Here are some natural examples:
Expressing gratitude
Thank you for helping me.
Showing appreciation
Thank you for everything you have done.
Accepting something
Yes, thank you.
Politely refusing
No, thank you.
Professional communication
Thank you for your time and consideration.
Strong appreciation
Thank you so much for your support.
Responding to a compliment
“You did a great job.”
“Thank you!”
These are all standard uses of thank you.
Thank You in Formal Writing
Thank you is completely appropriate in formal and professional writing.
You can use it in:
- Business emails
- Cover letters
- Job applications
- Thank-you letters
- Customer service messages
- Academic communication
- Professional correspondence
For example:
Thank you for taking the time to review my application.
Or:
Thank you for your prompt response.
A thank-you note is also a common expression in professional and personal writing.
Thank You in Emails
When writing an email, use thank you when directly expressing gratitude.
Correct
Thank you for sending the information.
Incorrect for this meaning
Thankyou for sending the information.
You can also use thank you near the end of an email:
Thank you for your assistance.
Thank you for your consideration.
Thank you for getting back to me.
These expressions are natural and professional.
Common Mistakes With Thank You
Mistake 1: Writing Thankyou When You Mean Thank You
This is the most important distinction to remember.
Wrong for the ordinary expression:
Thankyou for your help.
Correct:
Thank you for your help.
Mistake 2: Assuming Thankyou Is Always Wrong
This is also too broad.
Thankyou is recognized as a noun by Collins.
So it is better to say that thankyou is not the standard form for directly thanking someone, rather than claiming that the spelling can never occur.
Mistake 3: Confusing Thank-You With Thankyou
These forms can have different grammatical functions.
Thank you for the gift.
I wrote a thank-you note.
The gift was a thankyou for her assistance.
The first is the ordinary expression of gratitude. The latter two use the expression as a noun or modifier.
Mistake 4: Writing Thankyou in Professional Emails
Even though thankyou has dictionary support as a noun in some varieties of English, thank you is the appropriate choice when you are directly thanking someone.
For professional writing, clarity is more important than trying to force the words into one form.
How to Remember the Difference
Use this simple rule:
Thanking someone → thank you
Thank you for your help.
A noun or compound modifier → thank-you
She wrote a thank-you note.
Thankyou → recognized noun form in some dictionary usage
The gift was a thankyou.
If you are simply replying to someone or showing appreciation, choose thank you.
Thank You or Thankyou: Quick Comparison
Thank you is the standard expression used to directly show gratitude.
Thank-you is commonly used as a noun or compound modifier.
Thankyou can also be a noun in some dictionary and British English usage, but it is much less likely to be the best choice for ordinary American English writing.
Therefore, if you are writing:
Thank you for your help.
you should keep thank and you as two separate words.
Frequently Asked Questions
Is it thank you or thankyou?
When you are directly expressing gratitude, the standard form is thank you, written as two words. Thankyou can function as a noun in some dictionary usage, but it is not the usual form for directly thanking someone.
Is thankyou one word?
Thankyou is recognized as a noun in some dictionaries, especially in British English. However, when you are using the expression to thank someone, write thank you as two words.
Is thank-you correct?
Yes. Thank-you is a standard noun and compound modifier. Common examples include thank-you note, thank-you card, and thank-you gift.
Is thank you two words?
Yes. The ordinary expression of gratitude is thank you, written as two words.
Can I write thankyou in an email?
If you are directly thanking someone, use thank you. Although thankyou exists as a noun in some dictionary usage, it is not the standard choice for the ordinary expression.
Is thank you formal or informal?
Thank you works in both formal and informal English. It is appropriate for everyday conversation, professional emails, academic writing, and formal correspondence.
What is the difference between thank you and thanks?
Both express gratitude, but thanks is generally more informal and shorter. Thank you is more neutral and works well in both casual and formal situations.
Conclusion
When choosing thank you or thankyou, the best answer depends on how the expression is being used.
For the ordinary expression of gratitude, use thank you as two words:
Thank you for your help.
Thank-you is also correct when the expression functions as a noun or compound modifier, as in thank-you note or thank-you gift. Thankyou is recognized as a noun in some dictionary sources, particularly in British English, but it is not the normal form to use when directly thanking someone.
So, when in doubt, remember the simplest rule: if you are saying thanks to someone, write “thank you.”
Shirley Jackson, author at SeekIdiom, writes clear explanations of English idioms with examples to help learners improve vocabulary and communication skills.
