essentially

Writers often type "Their going to" when they mean "They are going to." That missing apostrophe changes the word from a possessive (their) to a contraction (they're), and it usually produces an ungrammatical sentence.

Quick answer

"Their going to" is incorrect when you mean "they are going to." Use they're (contraction) or the full form they are. Use their only to show possession (their report).

They're = they are → They're going to arrive soon.
They are = formal or emphatic → They are scheduled to present at 10.
Their = possessive adjective → their office, their idea (not before a verb).

Core explanation: why "Their going to" is wrong

Their is a possessive adjective that must modify a noun. They're is a contraction of they are and is required when the subject is followed by a verb or auxiliary.

If you can expand the phrase to they are and the sentence makes sense, use they're or they are.
If the word after the suspect word is a noun, they likely intended possession (their).
Never form a possessive by adding an apostrophe to their (their's is wrong).

Wrong → Right: Wrong: Their going to review the budget.
Right: They're going to review the budget.
Right (possession): Their laptop is on the desk.
Wrong → Right: Wrong: Their's a chance we'll finish early.
Right: There's a chance we'll finish early.

Punctuation, spacing, and hyphenation (quick checks)

Common mistakes: missing apostrophes or odd spacing (theyre, they 're) and incorrect possessive forms (their's). Use they're (one word with apostrophe) or they are; never their's.

Correct: they're, they are.
Incorrect: theyre, their's, they 're.
Watch spacing: "they're" has no space between they and 're.
Hyphenation rarely matters here. If a hyphened modifier feels awkward, rephrase: their premeeting notes → the notes before the meeting.

Wrong → Right: Wrong: Theyre going to upload the file.
Right: They're going to upload the file.
Wrong → Right: Wrong: Their 's notes were helpful.
Right: Their notes were helpful / They're taking notes.
Usage: Avoid using hyphens to force a contraction or possession; reword instead.

Real usage and tone: choosing they're vs they are

They're fits casual writing-texts, chats, informal emails. Use they are in formal writing, academic texts, or when you want emphasis.

Formal: use they are. Example: They are expected to deliver the report by Friday.
Casual: use they're. Example: They're meeting us at 7.
Emphatic: avoid the contraction. Example: They are the only team approved to proceed.

Rewrite help: paste-in fixes and stronger rewrites

When you see "Their going to..." choose one: replace with they're, write they are, or change the sentence to use a noun or active verb for clarity.

Casual quick fix: They're going to join us.
Formal quick fix: They are scheduled to join us.
Alternative rewrite: They plan to join us / Their plan is to join us (possession).

Rewrite examples: Wrong: Their going to finish the report tonight. → They're going to finish the report tonight.
Wrong: Their going to visit the lab tomorrow. → They are going to visit the lab tomorrow. (formal)
Wrong: Their going to handle the onboarding. → They will handle the onboarding / The onboarding is scheduled with them responsible.

Try your own sentence

Examples: wrong/right pairs (work, school, casual)

Copy the corrected form as a ready fix. Each wrong example uses their before a verb instead of they're or they are.

Work:
Wrong: Their going to send the revised slides by noon.
Right: They're going to send the revised slides by noon.
Work:
Wrong: Their going to chair the meeting tomorrow.
Right: They are going to chair the meeting tomorrow.
Work (possession): Wrong: Their presentation needs approval.
Right: Their presentation needs approval.
School:
Wrong: Their going to hand in the essay late.
Right: They're going to hand in the essay late.
School (possession): Wrong: Their research examines social trends.
Right: Their research examines social trends.
School:
Wrong: Their going to review the data in class.
Right: They are going to review the data in class.
Casual:
Wrong: Their going to crash at my place after the party.
Right: They're going to crash at my place after the party.
Casual (possession): Wrong: Their dog loves the park.
Right: Their dog loves the park.
Casual:
Wrong: Their going to love this new track.
Right: They're going to love this new track.

Fix your own sentence: a four-step checklist

Run these checks each time you see their/theyre/they're.

Read the suspect word and the next word. Is the next word a verb (going, arriving, doing)? If yes, you probably want they're/they are.
Expand to they are. If that reads naturally, replace with they're or they are.
If the next word is a noun, keep their (possession) or reword for clarity.
Read aloud: use they are for formal or emphatic tone, they're for casual tone.

Check example: "Their going to edit the draft." Expand → they are going to edit the draft? Yes → fix to They're/They are.
Check example: "Their supervisor approved it." Next word is a noun → keep their.

Memory trick: two fast tests to stop the mistake

Use two quick mental checks that take seconds and catch most errors.

Test A - Expand: Replace the word with they are. If it works, use they're/they are.
Test B - Next-word test: If the next word is a noun, keep their; if it's a verb (especially -ing), use they're/they are.

Quick example: "Their schedule is full." Expand → they are schedule is full? No → keep their. "Their going to start soon." Expand → they are going to start soon? Yes → use they're.

Similar mistakes to fix at the same time

When you spot this homophone error, also look for your/you're, its/it's, and there/their/they're. Fixing them in one pass improves clarity.

your vs you're: Your package arrived → You're expected at 9.
its vs it's: The app lost its settings → It's likely to be restored.
there vs they're vs their: There (place), they're (they are), their (possession).

Wrong → Right: Wrong: Your going to want this.
Right: You're going to want this.
Wrong → Right: Wrong: Its going to be tricky.
Right: It's going to be tricky.
Wrong → Right: Wrong: Their over there.
Right: They're over there. / Their books are over there.

FAQ

Is "their going to" ever correct?

Not to mean "they are." Use their only for possession before a noun. If you mean "they are," write they're or they are.

Should I use they're or they are in a formal email?

Prefer the full form they are in formal documents and academic writing. Use they're in casual emails or chat.

What's the fastest way to check a sentence?

Do the expand test: replace the suspect word with they are. If it reads naturally, use they're/they are; if not, you likely need their or there.

Is "theyre" acceptable in quick messages?

It's nonstandard. In very informal chats readers usually infer meaning, but use they're or they are in saved or professional messages.

How do I fix many errors at once in a document?

Run a grammar check to flag instances of their/theyre/they're, then apply the expand test to each flagged sentence. Also scan for your/you're and its/it's while editing.

Need a quick check?

When unsure, paste a sentence into a grammar tool or search for "their" followed by an -ing verb. Fixing a few of these errors makes your writing clearer and more professional.