Use than for comparisons and then for time. If you are weighing one thing against another — bigger, faster, more, less, rather — the word is than ("She runs faster than I do"). If you mean "at that time," "next," or "in that case," the word is then ("We ate, then we left"). They are never interchangeable, and only than ever follows a comparison.
Than is a conjunction — and, many argue, also a preposition — that introduces the second half of a comparison. It almost always follows a comparative word: an adjective or adverb ending in -er, or one paired with more, less, or fewer, or one of a small set of comparison words such as other, rather, else, and sooner.
The tell-tale sign is always a comparison. If you can spot a comparative word nearby — bigger, smaller, more, less, better, worse, rather, other — the correct spelling is almost certainly than.
Then is mainly an adverb, and it handles everything to do with time and consequence. It carries four everyday meanings:
Then can also act as an adjective meaning "at that time" — "the then prime minister" — and even as a noun — "we hadn't met before then." Every one of these uses points to a moment, a sequence, or a result. None of them involves comparing two things.
Seeing the two side by side makes the rule obvious:
This is an ear mistake, not a thinking mistake. In ordinary speech, than is unstressed and its vowel collapses to a soft "uh" sound (/ðən/), which is nearly identical to then (/ðɛn/). Because they sound almost the same when spoken quickly, the wrong one slips onto the page. The cure is to pause and ask what the sentence is actually doing — comparing, or telling time?
Then rhymes with when, and both are about time. So if your sentence could answer the question "when?", use then. If it couldn't — if you're setting two things against each other — reach for than. A second quick test: if you can swap in "next," "at that time," or "in that case" without changing the meaning, the word you want is then.
Both are correct, and the fussy "rule" you may have heard — that "than me" is wrong — is a myth. Traditional grammar treats than as a conjunction with an implied verb ("She's taller than I am"), which is why "than I" sounds formal. But "than me" treats than as a preposition, and that has been standard English for centuries. Use "than I" in formal writing if you prefer; "than me" is perfectly acceptable everywhere else.
One genuine caveat: case can change the meaning. "I like the dog more than him" means you prefer the dog to the man. "I like the dog more than he (does)" means you like the dog more than the man does. When the sentence could be read either way, spell the verb out.
This idiom catches people out because there's no obvious comparative, yet it still takes than, not then: "No sooner had we sat down than the phone rang." The word sooner is doing the comparing, so than is right. (Watch out — "no sooner ... when" is a common error too.)
These fixed phrases always use than. "Rather then" and "other then" are among the most frequent typos in English, but they are always wrong.
The logical pairing is always then: "If it's broken, then fix it." Some writers slip in than here because a choice can feel like a comparison, but it isn't — it's cause and effect.
The core distinction — than for comparison, then for time — is identical in American, British, Australian, and every other variety of English. The only genuine transatlantic wrinkle involves than in one phrase: different. Americans commonly say "different than," especially before a clause ("It's different than I remembered"). British English leans towards "different to," while "different from" is accepted everywhere and is the safest choice in formal writing. Crucially, that debate is between than, to, and from — then is never an option.
Comparisons take than; time and sequence take then. When in doubt, test whether the sentence answers "when?" (use then) or sets two things against each other (use than). Get that one question right, and you'll never mix them up again.
It's always 'better than.' 'Better' is a comparative word, and comparatives take 'than,' never 'then.' The same goes for every comparison: bigger than, worse than, more than, less than. So the saying is 'better late than never,' and 'I know better than to argue.' Reserve 'then' for time and sequence.
Both are correct. 'Than me' treats 'than' as a preposition and is standard in everyday English; 'than I' treats it as a conjunction with an implied verb ('taller than I am') and sounds more formal. Neither is wrong. Just watch for ambiguity: 'I like her more than him' and 'more than he does' mean different things.
'Different from' is accepted everywhere and safest in formal writing. 'Different than' is common in American English, especially before a clause ('different than I expected'), while 'different to' is common in British English. All three are standard in their contexts. The choice is between than, from, and to — 'different then' is always wrong.
Remember that 'then' rhymes with 'when,' and both deal with time. If your sentence could answer 'when?' — or you could swap in 'next,' 'at that time,' or 'in that case' — use 'then.' If you're comparing two things instead, use 'than.' In short: comparisons take than; time takes then.
It's always 'rather than.' 'Rather' signals a comparison or preference between two options, so it pairs with 'than': 'I'd rather walk than drive.' 'Rather then' is a very common typo but is never correct. The same rule applies to 'other than' and 'sooner than' — all comparisons, all 'than.'
