Interrogative sentences are used to ask questions in English. They may begin with a question word (like who, what, where), or with an auxiliary verb (like do, does, is). Forming a correct interrogative often involves do-support or inversion.

Question Words

Question words introduce a question with more detail about the type of information being requested. They always come first in the question.
Question WordUsage ExampleMeaningExplanation
whoWho* is at the door?asks about peopleused for subjects or objects
whatWhat* are you doing?asks about things or actionsused for objects or subjects
whereWhere* do you live?asks about placeused to ask about location
whenWhen* is the meeting?asks about timeused to ask about time
whyWhy* are you late?asks about reasonused to ask for a cause
howHow* do you make tea?asks about manner or processused to ask about method, condition, or degree
  • Note: After the question word, the sentence follows normal question grammar (do-support or inversion).

Can a question word be omitted in an information question in English?


No, it must always appear at the start.

English requires question words to appear at the very beginning to form an information question.

Do-Support

When forming questions in the simple present or simple past tense (except with auxiliary or modal verbs), English uses do-support. This means adding do, does, or did at the beginning of the question.
TenseExample (affirmative)Question with Do-SupportExplanation
Present SimpleYou like coffee.Do* you like coffee?use do for I/you/we/they
Present SimpleShe goes to school.Does* she go to school?use does for he/she/it; verb base form
Past SimpleThey played soccer.Did* they play soccer?use did for all subjects; verb base form

Question Word + Do-Support Example

SubjectSimple PresentQuestion FormUsage
youYou eat apples.Where do you eat apples?*question word + do-support
sheShe reads books.What does she read?*does + base verb
  • Important: No other auxiliary verb is needed; do/does/did carries the tense.

Inversion

Inversion means the auxiliary verb comes before the subject. This is used in questions that already have an auxiliary or modal verb.
Auxiliary/ModalAffirmative ExampleQuestion FormExplanation
be (am/is/are...)She is happy.Is* she happy?invert be + subject
have (present perfect)They have left.Have* they left?invert have + subject
canYou can swim.Can* you swim?modal + subject
willHe will call.Will* he call?modal + subject

Question Word + Inversion Example

SubjectVerbQuestion FormUsage
youareWhere are you?*question word + inversion
theyhaveWhat have they done?*auxiliary + subject
shecanWhy can she go?*modal + subject
  • No do-support is used here because the auxiliary/modal verb handles the question form.

Summary

  • Question words start questions when asking for specific information.
  • Do-support is used in simple present and past when no other auxiliary is present.
  • Inversion occurs when an auxiliary or modal verb is already in the sentence.
  • Place question words at the beginning if you need specific information.
  • Use the base form of the verb after do/does/did.
  • Other tenses (present continuous, present perfect, modals) use inversion, not do-support.

Final Examples

Question TypeExampleExplanation
Yes/No Simple PresentDo* you like pizza?do-support with *do
Yes/No Present PerfectHave* you finished?inversion with *have
Yes/No ModalCan* she help?inversion with modal
Question Word + Do-SupportWhere do you work?*question word + do-support
Question Word + InversionWhy is he late?*question word + auxiliary inversion

Last updated: Wed Jun 18, 2025

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