Avoiding repetition with auxiliary verbs

Avoiding repetition

1. Avoiding repetition

One way to avoid repeating information when we want to express disagreement is by using auxiliary verbs.

IMG UNIT 30-01
- I want to play videogames.
IMG UNIT 30-02
- I don't (want to play videogames)

2. Avoiding repetition with auxiliary verbs

When we want to show disagreement with something that has been said before (reference phrase), we usually avoid repeating the information that we already know. To do this, we use an auxiliary verb in the same tense as the reference phrase, and we follow this structure:

Subject +  auxiliary verb / modal verb
  • When the reference phrase is affirmative, the auxiliary verb will be negative.
    IMG UNIT 30-03
    - I am a bit hungry.
    IMG UNIT 30-04
    - I am not.
  • When the reference phrase is negative, the auxiliary verb will be affirmative.

    IMG UNIT 30-05
    - I am not afraid of horses.
    IMG UNIT 30-06
    - I am.
  • When the reference phrase is in present simple or past simple affirmative, no auxiliary verb is needed. However, we will have to use an auxiliary in the structure: do/does in the present simple and did in the past simple.
    IMG UNIT 30-10
    She likes chocolate but he doesn't.
    IMG UNIT 30-09
    They went to the beach but I didn't.

When the disagreement is in the negative form, the auxiliary verb can be contracted. However, if it's in the affirmative form, it won't.

- I'll go to the beach tomorrow.
- I won't / I will not.
- I won't go to the beach tomorrow.
- I will. / I'll

Remember!

We use auxiliary verbs when we want to show disagreement without repeating what has already been said. 
Sentence Structure
AFFIRMATIVE Subject + auxiliary or modal verb in NEGATIVE
I've already bought the present for Paula. I haven't. I'll do it tomorrow.
NEGATIVE Subject + auxiliary or modal verb in POSITIVE
I didn't watch the football match yesterday. I did. It was really exciting.