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Questions: Forming Yes/No, Wh-, and Polite Questions

9 min read 5 practice questions
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On this page 9 sections
  1. In 30 seconds
  2. Why this matters
  3. The college version
  4. Eli explains
  5. Worked example
  6. Key takeaway
  7. Quick check
  8. Study tools
  9. Sources & references

In 30 seconds

English builds questions by moving an auxiliary verb, or the verb be, in front of the subject: "Is Priya ready?" When a statement has no auxiliary, the helper do appears: "She works" becomes "Does she work?" Wh- questions open with a (what, where, when, who, why, how) and keep the auxiliary after it: "Where does the bus stop?" If the question word is the subject, nothing moves: "Who called you?" Question tags ("isn't it?", "do you?") and polite frames ("Could you tell me...?") complete the system.

Why this matters

Questions are how we find things out, and in college they do real work: clarifying an assignment in office hours, running an interview, or emailing a professor. A well-formed question gets a precise answer; a muddled one makes the listener guess. Knowing the difference between yes/no and wh- questions lets you choose the right tool, because a confirms a fact while a invites detail and explanation. The same machinery, auxiliaries, , and , reappears in question tags and polite forms, so learning it once pays off across speaking and writing. And since question patterns differ across languages, seeing the English system explicitly makes it easier to use rather than assuming the rules you already know.

The college version

Questions as a sentence type

English sentences come in four main types: declarative sentences make statements, imperative sentences give commands or requests, interrogative sentences ask questions, and exclamatory sentences express strong emotion. The interrogative is the type this lesson is about. The clearest clue is often the question mark at the end, but the real test is word order: a question moves part of the verb in front of the subject. Compare "The bus stops here" with "Does the bus stop here?" Both describe the same situation, but the second puts the auxiliary first and turns the sentence into a request for information. Noticing that difference, a reader or listener can hear a question coming before it even ends.

Yes/no questions: inversion and do-support

A yes/no question expects an answer of yes or no. English forms it by inversion: the auxiliary verb, or the verb be itself, moves in front of the subject. "Priya is ready" becomes "Is Priya ready?"; "They have finished" becomes "Have they finished?"; "Nina can swim" becomes "Can Nina swim?" Only the first auxiliary moves, so "The garden has been watered" becomes "Has the garden been watered?" Many statements have no auxiliary at all: "She works at the clinic." English never moves the main verb, so "Works she at the clinic?" is not a question in English. Instead, the helper do supplies the auxiliary: "Does she work at the clinic?" The main verb returns to its base form, so the -s that marked the statement disappears. In the past, did plays the same role: "You usually walked to work" becomes "Did you usually walk to work?" The verb be is the exception: it moves by itself and never borrows do, so we say "Are you ready?" and never "Do you be ready?"

Wh- questions: question word first

Wh- questions open with a question word, such as what, where, when, who, why, or how, and they ask for information rather than a yes or no answer. The question word goes first, and the auxiliary stays before the subject: "Where does the bus stop?" "When is the library open?" "Why did the train stop?" "How much does the course cost?" There is one important exception. When the question word is itself the subject of the clause, no auxiliary is added and no inversion happens. "Who called you?" works because who is the subject and the word order is exactly that of a statement. But "Who did you call?" needs do-support, because here you is the subject and who is the object. The same contrast appears with what: "What happened next?" treats what as the subject, while "What did you buy?" treats it as the object.

Question tags and polite questions

A is a short ending that turns a statement into a question seeking confirmation: "The bus has left, hasn't it?" The tag reuses the auxiliary or be of the statement plus a pronoun, and it follows the polarity rule: an affirmative statement takes a negative tag, and a negative statement takes an affirmative tag. "The bus hasn't left, has it?" A statement with no auxiliary takes do in the tag: "You like green tea, don't you?" English also softens direct questions in polite situations, often by embedding the question inside a frame such as "Could you tell me...?" or "Do you know...?" "Where is the station?" becomes "Could you tell me where the station is?" The embedded clause keeps statement word order, with no inversion and no do, even though the whole sentence is a question.

Common errors to watch for

The most frequent question-formation errors follow from the two rules above. Missing do-support: "What means this word?" should be "What does this word mean?" Missing inversion: "Why she left early?" should be "Why did she leave early?" Using be instead of do-support: "Are you agree?" should be "Do you agree?", because agree is a main verb and needs do, not be. (Be itself never borrows do: "Are you ready?", not "Do you be ready?") And after do, does, or did, the main verb always returns to its base form: "Does she works here?" is wrong, while "Does she work here?" is right. When you catch yourself producing one of these patterns, the fix is usually a single move: add the missing auxiliary, or move the one that is already there.

Eli, the EliExplains learning guide

Eli explains

The same idea, in plain words

Explain it like I’m 10

Questions are easy to build once you know one trick: find the verb. If the sentence already has a helper verb like is, have, or can, move that helper in front of the subject and you have a question: "The bus has left" becomes "Has the bus left?" If there is no helper, add the helper do: "She works" becomes "Does she work?" Then, if you need specific information, put a question word at the front: "Where does she work?" But if the question word is the person or thing doing the action, leave everything where it is: "Who works there?" The same helper system runs the tags at the end of questions, "The bus has left, hasn't it?", and the polite forms, "Could you tell me where the station is?"

Picture it like this

Think of a question as a doorbell. The sentence is the door, and the auxiliary is the button: you press it, by moving it in front of the subject, and the sentence opens into a question. When there is no button on the door, no auxiliary, you install one: do. The question word is the label on the door telling you what kind of room is behind it: where for places, when for times, who for people, why for reasons.

Where the picture stops working

The analogy has limits. A doorbell rings the same way every time, but a sentence can contain several auxiliaries and only the first one moves: "Has the garden been watered?" The label idea also breaks down, because question words do not just name the answer, they change the grammar of the sentence, as when who becomes the subject and no auxiliary appears at all. And unlike a doorbell, a question invites an answer rather than ending the exchange.

Worked example

A student is preparing a group presentation and needs three facts from her professor. She wants to know whether slides are required. The statement "The presentation needs slides" has no auxiliary, so she asks with do-support: "Does the presentation need slides?" Next she needs the deadline: the question word when goes first, then the auxiliary: "When does the draft have to be submitted?" Then she remembers the outline review. The person who will review is unknown, so the question word is the subject and nothing moves: "Who will review the outline?" As she leaves she checks one more thing with a tag: "You've seen our outline, haven't you?" And when the professor's assistant appears, she softens a request: "Could you tell me where the sign-up sheet is?" Every one of these questions uses the same machinery: an auxiliary before the subject, do when there is none, and a question word out front when specific information is needed.

Key takeaway

English questions run on one engine: put an auxiliary or the verb be before the subject, add do when there is none, and let a question word lead whenever you need specific information.

Quick check

3 questions here, of 5 in this lesson’s practice set. Answers stay hidden until you check.

Question 1 of 3foundational

Which question asks for a yes or no answer?

Choose an answer, then check it.
Question 2 of 3intermediate

Which sentence correctly turns "She works at the clinic" into a question?

Choose an answer, then check it.
Question 3 of 3intermediate

In the question "Who did you call?", what is the grammatical role of who?

Choose an answer, then check it.
Practice all 5

Keep learning

Ready to build on this? Continue to the next lesson.

Practice this lesson
Study tools & related lessonsYou’ll learn to · Common mistakes · Easily confused · Key vocabulary · Related

You’ll learn to

  • Define yes/no questions and wh- questions and distinguish them by the kind of answer each expects.
  • Explain how auxiliary verbs and the verb be move before the subject to form questions, and describe when do-support supplies an auxiliary.
  • Distinguish subject questions from object questions by the grammatical role of the question word.
  • Apply the polarity rule to build question tags for affirmative and negative statements.
  • Form polite indirect questions with frames such as "Could you tell me...?" and statement word order in the embedded clause.
  • Analyze common question-formation errors, including missing do-support and missing inversion, and correct them.

Common mistakes

  • Leaving out do-support, as in "What means this word?"

    Add do with the base form of the main verb: "What does this word mean?"

  • Keeping statement word order in a wh- question, as in "Why she left early?"

    Invert: put the auxiliary before the subject, so "Why did she leave early?"

  • Using do with be, as in "Are you agree?" or "Do you be ready?"

    Be moves by itself without do: "Do you agree?" and "Are you ready?"

  • Keeping the -s after do, as in "Does she works here?"

    After do, does, or did, the main verb returns to its base form: "Does she work here?"

  • Forgetting the polarity rule in tags, as in "She hasn't arrived, hasn't she?"

    A negative statement takes an affirmative tag: "She hasn't arrived, has she?"

Easily confused

Yes/no question vs. Wh- question

A yes/no question expects yes or no and forms by inversion alone; a wh- question opens with a question word, expects information, and keeps the auxiliary after the question word.

Subject question vs. Object question

In a subject question the question word is the subject, so no auxiliary appears ("Who called you?"); in an object question it is the object, so do-support appears ("Who did you call?").

Direct question vs. Indirect question

A direct question inverts ("Where is the station?"); an indirect question embeds the question in a frame and keeps statement word order ("Could you tell me where the station is?").

Key vocabulary

Interrogative sentence
A sentence that asks a question, such as "Is Priya ready?", and is one of the four main English sentence types.
Yes/no question
A question that expects yes or no as its answer, formed by placing an auxiliary verb or the verb be before the subject.
Wh- question
A question that opens with a question word (what, where, when, who, why, how) and asks for information rather than a yes or no answer.
Inversion
The word-order change that puts the auxiliary verb or the verb be before the subject in a question.
Do-support
The use of do, does, or did as the auxiliary in a question when the statement has no other auxiliary verb.
Question word
A word such as what, when, where, who, why, or how that opens a wh- question and names the kind of information requested.
Subject question
A question in which the question word is the subject of the clause, so no auxiliary is added, as in "Who called you?"
Object question
A question in which the question word is the object of the clause, so an auxiliary is used, as in "Who did you call?"
Question tag
A short auxiliary-or-be plus pronoun ending added to a statement, such as "isn't it?" or "do you?", following the polarity rule.
Indirect question
A question embedded in a frame such as "Could you tell me...?" in which the embedded clause keeps statement word order.

Sources & references

  1. Language Foundations Handbook — Sentences: Sentence Types — eCampusOntario Open Library
  2. Parts of Speech: Part 2 — Building on Foundations — Language Foundations Handbook — eCampusOntario Pressbooks
  3. Questions: yes-no questions (Are you feeling cold?) — English Grammar Today, Cambridge Dictionary — Cambridge University Press & Assessment (Cambridge Dictionary)
  4. Questions: wh- questions — English Grammar Today, Cambridge Dictionary — Cambridge University Press & Assessment (Cambridge Dictionary)
  5. Tags — English Grammar Today, Cambridge Dictionary — Cambridge University Press & Assessment (Cambridge Dictionary)
  6. Questions: typical errors — English Grammar Today, Cambridge Dictionary — Cambridge University Press & Assessment (Cambridge Dictionary)
  7. Politeness — English Grammar Today, Cambridge Dictionary — Cambridge University Press & Assessment (Cambridge Dictionary)
  8. Whether — English Grammar Today, Cambridge Dictionary — Cambridge University Press & Assessment (Cambridge Dictionary)
  9. Question forms — LearnEnglish Grammar, British Council — British Council (LearnEnglish)

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Researched 2026-08-21

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