How to see it
A colon comes after a complete sentence and says: here is the detail. That can be a list or an explanation. A semicolon joins two closely linked sentences, with no joining word. Each side could stand alone. So for both marks, the words before them must be a sentence. Sentence first, then the mark.
A worked example
We needed three things. Is that a sentence on its own? Yes, and a list comes after it. So a colon. A comma would make it look like four things. And a semicolon needs a sentence after it too.
The common mistake: a colon after words that are not a complete sentence ("I need: eggs")
The trap is a colon after words that are not a sentence. I need: eggs, flour and milk. I need is not complete. Need what? Drop the colon, or finish the sentence first: I need three things, then the colon.
Try one
Find the mistake, or choose N for no mistake.
- AThe match
- Bwas cancelled; because
- Cthe pitch was
- Dbadly flooded.
- Nno mistake
Show the answerHide the answer
Right: B, was cancelled; because
Because the pitch was badly flooded cannot stand alone, so no semicolon before it. The match was cancelled because the pitch was badly flooded.