Questions and negatives

Start with the auxiliary#

English yes-or-no questions usually move an auxiliary verb before the subject:

• She is ready. → Is she ready?
• They can swim. → Can they swim?
• You have finished. → Have you finished?

The main meaning stays the same, but the auxiliary-subject order tells the reader or listener that a question is being asked.

Use do with most simple forms#

Most ordinary verbs do not already contain an auxiliary in the present simple or past simple. Use do, does, or did:

• They work here. → Do they work here?
• He works here. → Does he work here?
• She called yesterday. → Did she call yesterday?

After does or did, use the base form of the main verb. Write Does he work?, not Does he works?

Make a statement negative#

Place not after the first auxiliary:

• The room is open. → The room is not open.
• We can attend. → We cannot attend.
• They have arrived. → They have not arrived.

With an ordinary simple-present or simple-past verb, add a form of do:

• I know the answer. → I do not know the answer.
• He knows the answer. → He does not know the answer.
• They left early. → They did not leave early.

Add question words#

Place who, what, where, when, why, or how before the auxiliary:

• Where does the bus stop?
• Why did the meeting end?
• How can we check the result?

There is one important contrast. When the question word is the subject, do not add do: Who called you? Here, who performs the action.

Common mistakes#

Avoid doubling the tense marking: Did she went? is incorrect because did already marks the past. Use Did she go?

Do not copy statement order into a direct question: Where you are going? should be Where are you going?

Before writing, identify the subject, the tense, and the first auxiliary. That short check usually gives the correct word order.