dummy auxiliary 'do'

NICE properties

 

1. If we want to form the negative counterpart of a sentence that does not contain an auxiliary verb, then we cannot simply add not. We need to insert a form of the verb do.

 

a Jon cycles to work every day.

b *Jon not cycles to work every day.

c Jon does not/doean't cycle to work every day.

 

The process of inserting do is called do-support in the linguistic literature.

 

2. Do is also used to form the interrogative versions of sentences that do not contain an auxiliary verb.

 

Jon cycles to work every day.

>

Jon does cycle to work every day.

>

Does Jon cycle to work every day?

 

To form the interrogative version of a sentence that does not contain an auxiliary verb, we first insert do before the main verb and then we invert this verb with the Subject. This inversion process is called Subject-Auxiliary Inversion. 

 

3. The third us of the dummy auxiliary is in contexts where auxiliaries get 'stranded'.

 

Does Jon cycle to work every day? He does.

John cycles all the way to work every day, and so does Tim.

 

Here, in the strings He does and so does Tim the auxiliary occurs without its main verb. This property has rather opaquely been referred to as code.

 

4. There is a fourth use of the dummy auxiliary, namely in so-called 'emphatic contexts'. Imagine a situation in which someone has just denied the truth of the sentence Jon cycle to work every day. If we are nevertheless convinced that this statement is true, we might indignantly respond by saying:

 

Jon DOES cycle to work every day!

 

Here, the capital letters indicate the heavy stress with which the auxiliary is pronounced.