Yes/no questions

English yes/no questions normally place an auxiliary before the subject. With be, move am, is, are, was, or were: Is she ready? Were they at work? With ordinary present verbs, use do or does; with ordinary past verbs, use did.

After do, does, or did, keep the main verb in its base form: Does he work here? Did they arrive? For negatives, place not after the auxiliary: She doesn't work here. They didn't arrive.

Short answers repeat the auxiliary rather than the whole sentence: Yes, she does. No, they didn't. Keeping the auxiliary visible makes both questions and answers clear.