CLAUSAL NEGATION
In clauses, negation is usually made with the particle not, by negating the finite operator (is not, cannot/isn’t, can’t, etc.), or a non-finite verb in a dependent clause (not wishing to disturb them). *Amn’t is not used in Standard English for the first-person singular; instead, I’m not (declarative) and Aren’t I (interrogative) are used. If no other auxiliary is present, a form of do (do, does, did) is brought in as operator. Compare the following positive and negative declarative clauses:
That man is the Secretary. That man is not/isn’t the Secretary.
He took the car. He didn’t take the car.
Ed always does the dishes. Ed doesn’t always do the dishes.
The last example here illustrates the use of does both as a lexical verb and as operator.
Don’t is the regular negative form used in second person imperatives: Don’t be late!
Some operators admit an alternative type of abbreviation with the subject in negative clauses. This occurs usually only with a pronoun. Both types are used in spoken English, the ‘not’ type being preferred in AmE:
They aren’t ready. They’re not ready.
She isn’t coming with us. She’s not coming with us.
He hasn’t finished. He’s not finished.
We haven’t got enough. We’ve not got enough.
