Subject-auxiliary Inversion - Overview

Overview

Subject–auxiliary inversion involves placing the subject after a finite auxiliary verb, rather than before it as is the case in typical declarative sentences (the canonical word order of English being subject–verb–object). The auxiliary verbs which may participate in such inversion (e.g. is, can, have, will, etc.) are described at English auxiliaries and contractions. Note that forms of the verb be are included regardless of whether or not they function as auxiliaries in the sense of governing another verb form. (For exceptions to this restriction, see Inversion with other types of verb below.)

A typical example of subject–auxiliary inversion is given below.

a. Sam has read the paper.

b. Has Sam read the paper?

Here the subject is Sam, and the verb has is an auxiliary. In the question, these two elements change places (invert). If the sentence does not have an auxiliary verb, this type of simple inversion is not possible. Instead, an auxiliary must be introduced into the sentence in order to allow inversion:

a. Sam enjoys the paper.

b. *Enjoys Sam the paper?

c. Does Sam enjoy the paper?

For details of the use of do, did and does for this and similar purposes, see do-support. For exceptions to the principle that the inverted verb must be an auxiliary, see Inversion involving non-auxiliary verbs below. It is also possible for the subject to invert with a negative contraction (can't, isn't, etc.). For example:

a. He isn't nice.

b. Isn't he nice?

Compare this with the uncontracted form Is he not nice? and the archaic Is not he nice?).