Question tags are short questions at the end of statements. Positive statement → negative tag. Negative statement → positive tag.
Rule one — opposite polarity
If the statement is positive, the tag is negative — and vice versa.
- He is here, isn't he?
- She doesn't smoke, does she?
Match the auxiliary
Use the same auxiliary as the statement. If there's no auxiliary, use 'do/does/did'.
- Tom put his books away after he'd finished his homework, didn't he?
- She has finished, hasn't she?
Modal tags
Modal verbs repeat in the tag.
- He can swim, can't he?
- They will come, won't they?
Tricky cases
'Let's go' → 'shall we?'. 'I am' → 'aren't I?'. Imperatives: 'Open the door, will you?'