Ellipsis with Auxiliaries and Infinitives (C1)

Ellipsis lets you leave out material that readers or listeners can recover from the context. With auxiliaries and infinitives, the words you retain show how the understood action relates to tense, modality or negation. The aim is concise expression without unclear reference.

Leave out a recoverable verb phrase

In verb phrase ellipsis, an auxiliary remains while the following verb phrase is understood. The missing material may include the main verb, its objects and other closely connected information.

Maya has submitted the revised proposal, but Leo hasn't.

Here, hasn't means hasn't submitted the revised proposal, not simply hasn't submitted.

I thought the printer would work, but it didn't.

Here, didn't means didn't work. The retained auxiliary expresses the actual past result.

The missing material need not be repeated word for word: its grammatical form adapts to the new subject or auxiliary. However, the intended meaning must be clear. If several actions are possible, repeating the main verb is often better than using ellipsis.

Choose the appropriate auxiliary

Retain an auxiliary that fits the meaning of the new clause. If the understood verb phrase has no auxiliary, use do, does or did.

Structure	Full version	With ellipsis
Modal	Nina can attend, and Omar can attend too.	Nina can attend, and Omar can too.
Perfect	Nina has replied, but Omar hasn't replied.	Nina has replied, but Omar hasn't.
Progressive	Nina is working, but Omar isn't working.	Nina is working, but Omar isn't.
Passive	Nina was invited, but Omar wasn't invited.	Nina was invited, but Omar wasn't.
Present simple	Nina agrees, but Omar doesn't agree.	Nina agrees, but Omar doesn't.
Past simple	Nina objected, and Omar objected too.	Nina objected, and Omar did too.

Agreement and tense belong to the clause containing the ellipsis, not automatically to the earlier clause.

She works from home, and I do too.

He doesn't drive now, but he did before his accident.

With be as the main verb, retain be, not do: I wasn't ready, but Elena was. Here, the omitted material is the complement ready rather than an action verb phrase.

Decide how much of an auxiliary chain to retain

When a clause contains several auxiliaries, ellipsis can begin at different points. More than one shortened version may therefore be possible.

“Has Lena been working late?”

“Yes, she has.” → has been working late

“Yes, she has been.” → has been working late

The shorter answer leaves more material understood. The longer answer retains the progressive auxiliary been and may give that part of the meaning greater emphasis.

Do not remove an auxiliary that is needed to express a new meaning.

“Did you send the attachment?”

“No, but I should have.” → should have sent the attachment

Here, have establishes the past-time reference of the unfulfilled obligation. I should would normally suggest a present or future obligation instead.

Do not normally use a contracted affirmative form of be or have as the final word in these elliptical clauses.

✓ “Are you ready?” “Yes, I am.”

✗ “Are you ready?” “Yes, I'm.”

✓ “Has she finished?” “Yes, she has.”

✗ “Has she finished?” “Yes, she's.”

Negative contractions are possible: I'm not, she hasn't, they aren't.

Quick check

Try one question now.

The receptionist has emailed the access code to every visitor, but the manager . Here, the missing words are has not emailed the access code to every visitor.

Check your answer when you are ready. No sign-in needed.

Retain infinitival to

After a word or expression that takes a to-infinitive, you can often retain to and omit the following verb phrase. This is common after expressions such as want to, hope to, intend to, would like to and be supposed to.

I haven't read the report yet, but I intend to.

You don't have to attend the reception unless you want to.

They asked me to explain, but I refused to.

For a negative infinitive, not to can remain:

I was going to complain, but I decided not to.

This means decided not to complain. Compare I didn't decide to complain, which denies making that decision rather than stating a decision against complaining.

The to must be an infinitive marker, not a preposition. You cannot shorten I'm looking forward to meeting you to I'm looking forward to: this expression needs a complement after the preposition to.

Keep be or have when the structure needs it

Do not assume that every infinitive must be shortened to to alone. Retaining be or perfect have can preserve an important structural or time distinction.

Copular be: I'm not a member, but I'd like to be. The omitted complement is a member.
Passive be: She wasn't shortlisted, although she had expected to be. The omitted word is shortlisted.
Perfect have: I haven't finished yet, but by Friday I expect to have. The understood phrase is finished; have presents completion by the future reference point.

These are different from I haven't finished yet, but I hope to, where to stands for the ordinary infinitive to finish. Choose the structure for the intended meaning rather than mechanically copying the earlier auxiliary.

Check reference and emphasis

Ellipsis is common in conversation, but it also makes formal writing less repetitive. In speech, a retained auxiliary often receives stress when it marks a contrast: I thought she wouldn't object, but she DID.

Be especially careful with possessives:

Anna revised her proposal, and Ben did too.

This can mean that Ben revised Anna's proposal or that he revised his own proposal. Context may resolve the reference; otherwise, state it explicitly.

Before using ellipsis, check:

Recovery: Is the omitted action or complement identifiable?
Grammar: Does the retained auxiliary fit the new subject and tense?
Meaning: Have you preserved necessary modality, negation and time reference?
Clarity: Could a pronoun or possessive be understood in two ways?

Keep an auxiliary, to, or to be / to have as the structure requires. Repeat the missing words whenever brevity would make the meaning uncertain.

1.Leave out a recoverable verb phrase

2.Choose the appropriate auxiliary

3.Decide how much of an auxiliary chain to retain

Try one question now.

4.Retain infinitival to

5.Keep be or have when the structure needs it

6.Check reference and emphasis

Now make it stick.