Hi All!

This is a method of changing sentences from Assertive to Interrogative.

We have the primary auxiliaries: forms of `to be`- is, am, are, was and were; forms of to do- do, does, and did; and forms of `to have`- have, has and had. Out of these those that end in `-s` -is, was, has and does- go with  third person singular nouns and pronouns.

We also have the Modal auxiliaries- shall, should; will, would; can, could and may, might.

A sentence can include a primary auxiliary or a modal auxiliary, as in: `He is here`; and `They should go there`.

By interchanging the position of the auxiliaries and the subject, we transform an Assertive sentence into an Interrogative. For the above two sentences we get: ` Is he here?` and `Should they go there?`

If a sentence does not contain an auxiliary we use a form of `to do` to form the Interrogative. Consider the following sentences:

`Science enables us to do good and bad`.

`Art allowed people to become popular hitherto`.

In the first sentence the subject is `Science` and it is in the third person singular. The form of `do` which goes with third person singular subjects is `does`.

So, use `does` to form the question. Put `does` before the subject and it becomes- `Does Science enable us to do good and bad?`

In the second sentence the verb `allowed` is in the past tense. So choose the form of `to do` which is in the past tense i.e; `did` to form the question, as in: `Did Art allow people to become popular hitherto?`

Other example sentences are: You have had your dinner. This becomes `Have you had your dinner?`

`They are over there`.  which becomes `Are they over there?`