then (than)

Then and than are short words with different jobs: than makes comparisons; then marks time, sequence, or consequence. A quick substitution test usually fixes the error: try "after that" for then and "compared to" for than.

Below are clear rules, many wrong/right pairs for work, school, and casual contexts, quick rewrite templates, and memory tricks to stop the mistake.

Quick answer

Use than for comparisons (X is bigger than Y). Use then for time, sequence, or result (first X, then Y; if X, then Y).

Than = comparison (compare A to B).
Then = time/sequence or consequence (next, after that, therefore).
Quick test: if "after that" fits, use then. If "compared to" or a comparative adjective fits, use than.

Core explanation: choose by function, not sound

Than is a conjunction for comparisons: taller than, fewer than, more than. Then is an adverb that places events in time, shows order, or gives a result: first... then..., if X, then Y.

Comparison? → than. Order/result? → then.
Substitute to check: replace the suspect with "after that" (for then) or "compared to" (for than).
Examples:
- Comparison: She is taller than her sister.
- Sequence: Finish the report, then send it to me.

Grammar: common patterns and punctuation

Comparative patterns: [comparative adjective/adverb] + than + [second item] (e.g., more experienced than, faster than).

Temporal/consequential patterns: then follows sequence markers or appears in conditionals: "First X, then Y", "If X, then Y", "By then...".

Pattern examples: "more A than B", "A-er than B", "less A than B".
Comma use: put a comma when then joins independent clauses (We ate, then we left). In conditional clauses, a comma after the if-clause is conventional: "If X, then Y".
Pronouns: formal comparisons can use than + pronoun (She is taller than I), though than + me is common informally.

Comparative-pattern: More candidates applied than last year.
Conditional-pattern: If the code passes tests, then we'll merge the branch.

Real usage: work, school, and casual tones

Register changes optional words and formality, but not the core rule: than = compare; then = sequence/result. Keep punctuation for clarity in formal writing.

Work: use than for metrics and then for process steps; add commas to separate clauses.
School: comparisons need than; instructions and steps usually use then with commas.
Casual: speech often omits punctuation-write to reflect the intended meaning.

Work (wrong): 'If budget allows then we'll hire.' → Right: 'If budget allows, then we'll hire.'
School (wrong): 'He is better at history then science.' → Right: 'He is better at history than science.'
Casual (wrong): 'Let's eat then watch a movie.' → Right: 'Let's eat, then watch a movie.' (If comparison intended: 'I prefer eating to watching movies.')

Examples: grouped wrong → right pairs (copy-paste fixes)

Each wrong sentence shows a common slip; the right sentence is the fixed version. Use these as templates to correct similar cases.

Wrong: She is taller then her sister.
Right: She is taller than her sister.
Wrong: I'd rather go to the park then the mall.
Right: I'd rather go to the park than the mall.
Wrong: If you arrive early than you'll get a good seat.
Right: If you arrive early, then you'll get a good seat.
Wrong: More people prefer tea then coffee.
Right: More people prefer tea than coffee.
Wrong: First we bake the cake than we ice it.
Right: First we bake the cake, then we ice it.
School - Wrong: She finished quicker then her classmates.
School - Right: She finished quicker than her classmates.
Work - Wrong: Send the invoice then the client will pay.
Work - Right: Send the invoice, and then the client will pay.
Casual - Wrong: I like pizza then pasta.
Casual - Right: I like pizza more than pasta.
Work - Wrong: We met at noon than went to the conference.
Work - Right: We met at noon, then went to the conference.

Rewrite help: quick fixes you can paste into your sentence

If the substitution test shows the wrong word, use one of these short rewrite templates to restore clarity without changing tone.

Comparison: 'X is [comparative adjective] than Y.' or 'I prefer X to Y.' (use 'to' with prefer in formal contexts).
Process/sequence: 'First [action], then [next action].' or '[Action], then [result].'
Conditional clarity: 'If [condition], then [result].' - include the comma for formal writing.

Rewrite:
Wrong: 'She finished quicker then her classmates.' →
Correct: 'She finished quicker than her classmates.'
Rewrite:
Wrong: 'I'll call you then you decide.' →
Correct: 'I'll call you, then you decide.' OR (if comparison) 'I'll call you sooner than you will.'
Rewrite:
Wrong: 'I'd prefer Monday then Tuesday.' →
Correct: 'I'd prefer Monday to Tuesday.'
Rewrite:
Wrong: 'If funding is approved then we expand' →
Correct: 'If funding is approved, then we will expand.'
Rewrite:
Wrong: 'We worked longer then expected.' →
Correct: 'We worked longer than expected.' OR 'We worked longer, then we stopped.' (choose based on meaning)
Rewrite:
Wrong: 'Do that then me.' →
Correct: 'Do that, then me.' OR 'Do that before me.' (choose based on intended meaning)

Try your own sentence

Test the whole sentence rather than the isolated phrase; context usually makes the correct choice clear.

Memory tricks and fast heuristics

Use these quick cues when editing.

'After that' test: replace the suspect with 'after that'. If it fits, use then.
'Compared to' test: replace with 'compared to' or insert a clear comparative adjective. If it fits, use than.
Mnemonic: than contains an 'a' - link it with 'comparison' as a simple cue.
Read aloud: sequence sentences flow with small pauses ('Do X, then Y'); comparisons sound like 'X than Y' with comparative stress.

Usage test: 'She is nicer ____ him.' Replace with 'compared to' → 'She is nicer compared to him' → use 'than'.
Usage test: 'We eat ____ we work.' Replace with 'after that' → doesn't fit → reword for clarity.

Similar mistakes to watch for

When you fix then/than, also check other common small-word errors to save time.

they're / their / there - contraction vs. possessive vs. place (Wrong: 'Their going' →
Right: 'They're going').
its / it's - possessive vs. contraction (Wrong: 'Its raining' →
Right: 'It's raining').
affect / effect - verb vs. noun (Wrong: 'That will effect the plan' →
Right: 'That will affect the plan').
who / whom - subject vs. object (Use whom when it's the object of a verb or preposition in formal writing).

Usage: Wrong: 'Their going to present then the meeting.' →
Right: 'They're going to present, then the meeting starts.'
Usage: Wrong: 'Its later then I thought.' →
Right: 'It's later than I thought.'

Hyphenation and spacing: nothing special for then/than

Neither then nor than is hyphenated. Treat them as ordinary short words - one word, no internal hyphens.

Never hyphenate: not 'the-n' or 'th-an'.
Use a comma before then when it links independent clauses: 'We tested it, then we deployed it.'
Use a single space after punctuation: standard spacing rules apply.

Usage: Wrong: 'She is taller,then her sister.' →
Right: 'She is taller than her sister.'
Usage: Correct spacing: 'First we meet, then we decide.'

Spacing and punctuation tips

Comma placement often clarifies whether you mean then or than. Adjust punctuation to reflect the intended relationship.

In conditional clauses put a comma after the if-clause: 'If you finish early, then we can leave.'
When then connects two independent clauses, use a comma: 'She called, then she emailed.'
Do not insert a comma between a comparative adjective and than: 'taller than him' (no comma).

Usage: Wrong: 'If you come then we'll start.' →
Right: 'If you come, then we'll start.'
Usage: Wrong: 'He's taller, than I remembered.' →
Right: 'He's taller than I remembered.'

FAQ

When do I use then instead of than?

Use then for time, sequence, or consequence (first this, then that; if X, then Y). Use than only for comparisons (bigger than, fewer than).

Is than ever optional like then can be in conditionals?

No. Than is required for comparisons. Then can sometimes be omitted in casual speech in conditional sentences, but omitting than removes the comparative meaning.

How can I quickly check many occurrences in a long document?

Search for every 'then' and 'than' and run the substitution tests: try 'after that' for then; try 'compared to' or insert a comparative adjective for than. Batch-fix and re-read each sentence for meaning.

What about using 'prefer' - should I write 'prefer X than Y'?

Formal usage prefers 'prefer X to Y' (I prefer coffee to tea). 'Prefer X than Y' is common in nonstandard usage and should be avoided in formal writing.

I see 'then' used in 'more than' sometimes - is that wrong?

If you mean a comparison, it must be 'more than'. 'More then' is a misspelling. Use 'more than' for comparisons (e.g., more than 10 people).

A quick habit that saves you edits

Before you send an important email or submit a document, scan every then/than and run the short substitution tests. Fixing a few instances takes seconds and avoids clarity errors.

If you'd like, paste one tricky sentence where prompted above and get a direct rewrite you can paste back into your document.