Punctuation and apostrophes

The first fault is a word that sounds like the word you meant. “Going over there notes” passes the ear test, because there and their are pronounced the same. Their shows who owns something, there points at a place, and they're is short for they are. Since spelling cannot be heard, the only reliable check is to substitute: swap in they are, and if the sentence stops making sense, you wanted their or there instead.

The second fault is a missing apostrophe, and the same substitution trick works. Its and it's are the pair that catch people out, because the family rule is backwards here: normally an apostrophe means possession, but with it the apostrophe always means the missing letter in it is. “Its important” is short for it is important, so it needs the mark; “the dog wagged its tail” shows possession and takes none.

Plural possession is the third case, and it is where the apostrophe moves. One student's notes becomes two students' notes, because the mark follows the owner rather than sitting inside the word. With an irregular plural like children, the mark goes before the s — children's — because the plural does not end in s to begin with.

None of this is caught by reading aloud, so build a habit instead: after the piece is finished, check only the apostrophes and the sound-alike words, in a pass of their own. A separate pass is far more accurate than trying to spot them while you are still deciding what to say.