Punctuation that trips up English learners

Punctuation is where a good English learner's writing gives itself away. The grammar is right, the vocabulary is right, and then a comma in the wrong place makes a sentence read as though it were translated. These are the five marks that cause it, in the order they cause it.

The colon, and what it is actually for

A colon says: what follows explains or lists what came before it. That is its whole job. Think of it as an arrow pointing forwards.

Three correct uses, and they are the only three you need:

• Before a list. We visited three cities: Edinburgh, Glasgow and Durham.
• Before an explanation. There was one problem: nobody had a key.
• Before a quotation you are introducing formally. She said only this: "Not today."

The rule learners break most: a complete sentence must come before the colon.

• ✘ The three cities we visited were: Edinburgh, Glasgow and Durham.
• ✔ We visited three cities: Edinburgh, Glasgow and Durham.
• ✔ The three cities we visited were Edinburgh, Glasgow and Durham.

"The three cities we visited were" is not a sentence, so the colon has nothing to point back to. Either finish the sentence first or drop the colon.

After the colon: in British English, lower case unless what follows is a proper noun or a full quoted sentence. American English capitalises more freely. Pick one and be consistent — we teach the British convention, because that is the English our students are surrounded by.

The semicolon, which is not a comma

A semicolon joins two statements that could each stand alone but belong together. It is stronger than a comma and weaker than a full stop.

• ✔ The train was late; we missed the tour.
• ✘ The train was late, we missed the tour. — this is a comma splice, and it is the single most common punctuation error in learner writing.
• ✔ The train was late, so we missed the tour. — a comma is fine once you add a joining word.

The test: could you put a full stop there instead? If yes, a semicolon is allowed. If no, it is wrong.

Its other use is separating items in a list that already contains commas: We visited Edinburgh, the capital; Glasgow, the largest city; and Durham, which has the cathedral.

The apostrophe, which is only doing two things

Possession and omission. That is all. Every apostrophe error is a confusion between those two or an apostrophe where neither applies.

• Possession: the student's bag (one student), the students' bags (several students). Singular: apostrophe then s. Plural already ending in s: s then apostrophe.
• Omission: it's = it is. don't = do not. they're = they are.

The three that catch almost everybody:

• its vs it's. It's always means "it is". Its is possessive and has no apostrophe — like his, which nobody writes as hi's. The city has its own accent.
• your vs you're. You're = you are. Your bag.
• Plurals never take one. ✘ photo's, ✘ the 1990's, ✘ two pizza's. Just add s.

The comma, and the four places it belongs

Commas are where learners over-apply what their own language does. English uses fewer than Spanish, German or Russian, and more than Chinese or Japanese.

1. Between items in a list. lessons, excursions and meals. British English usually omits the comma before "and"; American English usually keeps it. Either is acceptable; be consistent.
2. Before a joining word linking two full statements. It rained, so we went to the museum.
3. Around extra information you could remove. Durham, which has the cathedral, is twenty minutes away. Remove the middle and the sentence still works — that is the test. If removing it changes the meaning, no commas: The student who arrived late missed the test.
4. After an introductory phrase. On the first morning, everybody sits a placement test.

Where it does not belong: between a subject and its verb. ✘ The students who arrived on Monday, sat the test. That comma is the most common one to delete from learner writing.

The dash, and why it is not a hyphen

Three different marks, and word processors hide the difference.

• Hyphen (-) joins words: a two-week course, a well-known city, fourteen-year-old.
• En dash (–) means "to" in a range: 09:00–13:00, Monday–Friday, pages 10–14.
• Em dash (—) interrupts a sentence, like a stronger comma: The cathedral — which is free — takes an hour.

A hyphen where an en dash belongs is the mistake in almost every learner timetable. 09:00-13:00 should be 09:00–13:00.

Either, neither, and the agreement that goes with them

Not punctuation, but it sits in the same category of small things that give writing away.

• either … or, neither … nor. Never mix them: ✘ neither this or that.
• Neither is already negative. ✘ I don't like neither of them. ✔ I like neither of them. ✔ I don't like either of them.
• The verb agrees with the nearer subject. Neither the teachers nor the student was late. · Neither the student nor the teachers were late.
• "Me neither" is the natural spoken reply, not "me too" — "I don't like coffee." "Me neither."

How to actually improve this

Not by memorising rules. Two things:

Read your writing aloud. A comma is a short pause and a semicolon is a longer one. If you run out of breath, a mark is missing; if you stop where you did not mean to, one is spare. This catches more than proofreading does, because your ear knows English rhythm before your eye knows the rules.

Fix one mark at a time. Spend a week putting apostrophes right and ignore everything else. Then a week on commas. Trying to fix five at once fixes none.

Punctuation is also the one part of English a fortnight abroad does not improve much — it is a writing skill, and a study holiday is mostly a speaking one. If written accuracy is the goal, our general English course runs over more weeks with written work marked, and study holiday, summer camp, or language course explains why those are different products.

For the speaking half, phrasal verbs with up is where most learners get the fastest return.