Lesson

More on leaving out words after auxiliary verbs

Advanced ellipsis

≈ 20 min 8 block(s)

Text

More on leaving out words after auxiliary verbs

This lesson explains how auxiliary verbs (be, have, do, modals, will, etc.) can stand alone and replace a main verb or a phrase. We focus on correct omissions (ellipsis) after auxiliaries in short answers, coordinated clauses, and contrasts — and when you must use do-support instead of omitting words.

  • Auxiliaries can act as pro-forms and replace a main verb: e.g., "I have" (= "I have finished").
  • Use ellipsis when the auxiliary already indicates tense, aspect, and polarity.
  • If no auxiliary is present, use do-support for questions and short answers: "Do you agree? Yes, I do."
  • Match tense and polarity: the auxiliary you omit with must agree with the omitted verb phrase.

Table

Ellipsis after auxiliaries (examples)

Structure Use Example (full) Example (elliptical)
Present perfect (have) Short answer / replacement Have you sent the report? — Yes, I have sent the report. Have you sent the report? — Yes, I have.
Modal auxiliary (can/could) Short answer / contrast She can approve the budget and I can approve the budget. She can approve the budget and I can.
Future (will) Short answer / contrast He will attend the meeting and I will attend the meeting. He will attend the meeting and I will.
Past simple (did) Short answer / contrast when do-support was used They completed the audit and we completed the audit. They completed the audit and we did.
Be as auxiliary Short answer / ellipsis Is the team ready? — Yes, the team is ready. Is the team ready? — Yes, it is.
No auxiliary present Requires do-support in questions/short answers You like the proposal? (incorrect) / Do you like the proposal? — Yes, I do. Do you like the proposal? — Yes, I do.

Tip

Key rule: When can you leave words out?

Leave out the repeated verb phrase only when an appropriate auxiliary is present and it matches tense and polarity.

  • If an auxiliary (have, be, will, can, did, etc.) appears, it can stand alone to avoid repetition.
  • If there is no auxiliary, you must use do-support for questions/short answers in simple present/past.
  • Keep agreement: auxiliary must match subject, tense and positive/negative form.

Do not omit the verb phrase unless the auxiliary clearly carries the meaning.

Example

Examples in context

Have you submitted the proposal? — Yes, I have.

The manager approved the document, and the director did too.

I can't join the video call, but she can.

They won't attend the training, but we will.

Tip

Common mistakes to avoid

These errors come up frequently when learners try to omit words after auxiliaries.

  • Omitting the main verb when there is no auxiliary (forgetting do-support): "You like the plan? — Yes, I." (incorrect).
  • Mismatching tense or polarity: using a positive auxiliary after a negative reference: "She didn't call, but he has." (wrong if tense doesn't match).
  • Leaving out necessary auxiliaries in questions: "You finished the report?" (spoken may be acceptable informally, but standard written English requires "Did you finish the report?").
  • Adding an auxiliary that doesn't match the omitted verb phrase: "He can play the piano and I will." (sounds odd unless referring to future willingness).

When in doubt, write the full verb phrase to avoid ambiguity.

Quiz

Choose the correct sentence that uses ellipsis after an auxiliary:

Hint: Look for the auxiliary that can replace the verb phrase and match tense/aspect.

Quiz

Complete: They didn't attend the meeting, but we _____.

Hint: Think about the auxiliary used for past simple short answers.

Quiz

Which sentence is NOT acceptable in standard written English?

Hint: Focus on whether the second clause has an appropriate auxiliary to replace the verb phrase.

Key Points

GrammarPoint

auxiliary verb

noun CEFR B1 //ɔːɡˈzɪljəri vɜːrb//

A verb used with a main verb to form tenses, voice, mood, or questions (e.g., do, have, be, will, can).

Do you have an update?

GrammarPoint

ellipsis

noun CEFR B2 //ɪˈlɪpsɪs//

The omission of words that are understood from context, often to avoid repetition.

They completed the plan, and we did too.

GrammarPoint

do-support

noun CEFR B2 //duː səˈpɔːrt//

Using the auxiliary 'do' to form questions, negatives, or emphatic statements when no other auxiliary is present.

Do you agree with the proposal?

Vocabulary

short answer

noun CEFR B1 //ʃɔːrt ˈænsər//

A brief response that often uses an auxiliary verb alone (e.g., Yes, I have / No, she didn't).

Have you finished? — Yes, I have.

Vocabulary

modal

noun CEFR B1 //ˈmoʊdəl//

A helper verb that expresses ability, permission, possibility, or obligation (can, could, may, must).

She can review the contract tomorrow.

GrammarPoint

pro-form

noun CEFR C1 //proʊ fɔːrm//

A word that stands in for another phrase or clause (auxiliaries often act as pro-forms in ellipsis).

In 'I have, you have, she has,' 'has' is a pro-form for 'has finished.'