in masse (en masse)

You probably typed their when you meant they're (they are). That swap changes meaning: their = possession; they're = contraction of they are. Below are quick rules, clear tests, plenty of wrong/right pairs for work, school, and casual contexts, ready-to-copy rewrites, and easy habits to fix the error for good.

Quick answer

"Their going to" is incorrect. Use they're (they are) or the full they are when the meaning is "they are" + verb. Use their only to show possession (their book, their idea).

Wrong: Their going to be late.
Right (casual): They're going to be late.
Right (formal): They are going to be late.

Core explanation: the one-line test

Their = possession. They're = they are (contraction). The fastest check: replace the word with "they are." If the sentence still makes sense, use they're or they are. If it needs ownership, use their.

If it answers "whose?", choose their.
If it answers "what are they doing?", choose they're / they are.

Wrong: Their going to update the spreadsheet.
Right: They're going to update the spreadsheet.

Spacing and punctuation: apostrophes matter

This is not a spacing issue. The error mixes up two different words and omits an apostrophe in the contraction. Contractions need an apostrophe where letters are omitted: they're = they + 're (they are).

They're = they + are (apostrophe replaces the missing a).
Their = possessive; no apostrophe.
Basic spellcheck may not flag their because it's a valid word; grammar-aware tools or a quick swap test catch the mistake more reliably.

Wrong: Their going to; you'll see.
Right: They're going to; you'll see.

Hyphenation note: contractions don't get hyphens

Don't write they-'re, they-re, or theyre. Use an apostrophe for contractions and avoid hyphenating contractions. Hyphens belong to compound modifiers (e.g., long-term plan), not to pronoun + verb contractions.

Wrong: They're-ready team will start tomorrow.
Right: The team that is ready will start tomorrow.

Real usage and tone: pick the right register

They're is fine in conversation, chat, and most emails. They are suits formal documents, policies, academic writing, or when you want emphasis. Match the tone of the rest of the text.

Internal chat: use they're-it's natural.
Client-facing or academic: prefer they are or rephrase to avoid contractions.
If unsure, default to the full form in formal contexts.

Work (chat): "They're fixing the bug now." - fine.
Work (client email): "They are implementing the change next week." - preferred.
School (paper): "They are likely to pass with those revisions." - formal choice.

Try your own sentence

Test the whole sentence rather than the phrase alone-context usually makes the correct choice obvious.

Real examples - wrong/right pairs (work, school, casual)

Grouped by context so you can copy the exact tone you need. Each wrong line is followed by a correct rewrite.

Work - Wrong: Their going to finish the budget by noon.
Work - Right: They're going to finish the budget by noon.
Work - Wrong: Their going to send the revised slides after lunch.
Work - Right: They're going to send the revised slides after lunch.
Work - Wrong: Are their going to attend the stakeholder meeting?
Work - Right: Are they going to attend the stakeholder meeting?
School - Wrong: Their going to score high on the exam.
School - Right: They're going to score high on the exam.
School - Wrong: I think their going to hand in the assignment late.
School - Right: I think they're going to hand in the assignment late.
School - Wrong: Are their going to present during lab tomorrow?
School - Right: Are they going to present during lab tomorrow?
Casual - Wrong: Their going to be so surprised when we show up.
Casual - Right: They're going to be so surprised when we show up.
Casual - Wrong: Their going to text you later, I think.
Casual - Right: They're going to text you later, I think.
Casual - Wrong: I heard their going to throw a party on Saturday.
Casual - Right: I heard they're going to throw a party on Saturday.

Quick rewrites: ready-to-copy fixes for longer sentences

Use the first rewrite for a direct fix, the second for formal tone, and the third when a tense or clarity adjustment helps.

Wrong: Their going to finish the pilot episode and release it to stream next week.
Rewrite: They're going to finish the pilot and release it next week.
Wrong: Their going to rework the slides, so we might need more time.
Rewrite: They're reworking the slides, so we may need more time.
Wrong: Their going to be late because the train was delayed by maintenance.
Rewrite: They were delayed by maintenance, so they're going to be late. (Or: They are delayed and will be late.)
Wrong: Their going to handle the refunds next week which could slow the process.
Rewrite: They're handling refunds next week, which could slow the process.

Fix-your-own-sentence checklist

Run these three quick steps whenever you spot their before a verb-like phrase.

Step 1: Do the "they are" swap test-if it reads correctly, use they're/they are.
Step 2: Pick the tone-they're for casual, they are for formal or emphasis.
Step 3: Reread and adjust tense or clarity with a quick rewrite if needed.

Example - Wrong: Their going to reschedule the demo but not sure when.Fixed: They're going to reschedule the demo, but they haven't picked a date yet.

Memory tricks and habit fixes

Simple routines beat rules when you're typing fast. Use the prompts below until the correction becomes automatic.

Mnemonic: "Their" = belongs to them. "They're" = they are (doing something).
Habit: when you type their + verb, pause-either add an apostrophe and re, or expand to they are.
Practice: write three correct sentences with they're each morning for a week to build muscle memory.

Similar mistakes to watch for

If you mix up their/they're, you may also swap your/you're and its/it's. Apply the same swap test: replace with "you are" or "it is/it has" to check meaning.

your vs you're - test with "you are".
its vs it's - test with "it is" or check for possession.
there vs their vs they're - location vs possession vs they are.

Wrong: Your going to love this recommendation.
Right: You're going to love this recommendation.
Wrong: Its going to be a long drive.
Right: It's going to be a long drive.

FAQ

Is "their going to" correct?

No. "Their" is possessive and cannot replace "they are." Use they're or they are when the meaning is "they are" followed by a verb.

When should I write they are instead of they're?

Use they are in formal writing or when you want emphasis. They're suits conversational writing, emails, and dialogue.

How can I remember the difference quickly?

Ask "whose?" If yes, use their. Ask "what are they doing?" If yes, use they're/they are. The swap test ("replace with they are") is fast and reliable.

Will spellcheck catch "their going to"?

Basic spellcheckers may not, because their is a correctly spelled word. Use a grammar-aware checker or read the sentence aloud to catch contextual mistakes.

Is it acceptable to drop the apostrophe in contractions (theyre)?

No. In standard writing, contractions require the apostrophe. Omitting it is a typo and looks unprofessional.

Quick check before you send

Before you hit send, run the "they are" swap test, choose the tone you want, and copy a rewrite if you need a fast fix. A one-second pause when you type their + verb prevents a visible error.