Common confusions

Their shows possession — something belongs to them (“their books”). There points to a place, the opposite of here (“over there”). They’re is short for “they are” (“they’re late”). If you can swap in “they are” and it still makes sense, use they’re.

Your shows possession (“your jacket”). You’re is short for “you are” (“you’re right”). The test is the same: if “you are” fits, use the apostrophe form.

This pair trips people up because the rule feels reversed. Usually an apostrophe-s shows possession (“the dog’s tail”), but its is the exception: the possessive has NO apostrophe (“the dog wagged its tail”). It’s is only ever short for “it is” or “it has”. So the test is one-way: if you can’t expand it to “it is”, drop the apostrophe.

Two is the number 2. Too means “also” or “excessively” (“me too”, “too hot”) — the meaning “also” has an extra “o”, and so does the word. To is everything else: direction (“to school”) and the start of a verb (“to run”).

Than is for comparisons (“taller than”, “rather than”). Then is for time and sequence (“first this, then that”). Memory hook: than for comparison, then for time.

Were is the past tense of “are” (“they were here”); we’re = “we are”; where asks about a place (it even contains “here”). The same possessive-vs-contraction logic as its/it’s covers whose (belonging to whom — “whose bag?”) versus who’s = “who is”.

lose vs loose: lose (one “o”) is the verb — to misplace or not win; loose (two “o”s, rhymes with goose) means not tight. could’ve, never “could of”: “could’ve” is short for “could have” — it only sounds like “could of”, which is always wrong (also would’ve, should’ve). affect vs effect: usually affect is the verb (Affect = Action) and effect is the noun, the End result you can put “an” in front of (“an effect”).