Is it..? Have you..? Do they..? Etc.

This lesson explains how to form English questions using auxiliary verbs (be, have, do) and modals. You'll learn how to invert the subject and auxiliary, when to use do-support, and where to place question words (who, what, where, when, why, how).

• Use BE to ask about identity, state, or progressive actions: Is it ready? Are they coming?
• Use HAVE for present perfect questions: Have you finished the report?
• Use DO/DOES/DID when there is no other auxiliary: Do they work remotely? Did you approve it?
• Place question words at the beginning: Where did you save the file?

Invert the subject and the auxiliary to form questions. If there is no auxiliary, use do-support.

• With auxiliary or modal: Auxiliary + subject + main verb → 'Have you completed it?'
• Without auxiliary (present simple/past simple): Do/Does/Did + subject + base verb → 'Do they attend weekly meetings?'
• With question words: Question word + auxiliary + subject + verb → 'When did you send the file?'

Remember: If the sentence already has an auxiliary (be, have, modal), invert it with the subject. Otherwise add do/does/did.

Watch for these universal errors when forming questions.

• Forgetting to invert subject and auxiliary: writing 'You have finished?' instead of 'Have you finished?'
• Using two auxiliaries unnecessarily: 'Do you can attend?' is incorrect.
• Omitting do-support in simple present/past: 'She likes it?' should be 'Does she like it?'
• Placing question words in the wrong position: 'You did where save it?' instead of 'Where did you save it?'

Focus on word order: question word → auxiliary → subject → main verb.