The anomalous finites are used to form inverted sentence patterns.
- I had no sooner got into the train than it steamed off.
- No sooner had I got into the train than it steamed off.
To avoid repetition of principal verbs
The anomalous finites are used in short answers to avoid the repetition of principal verbs.
- ‘Do you want this?’ ‘Yes, I do.’ (= Yes, I want that.’)
- ‘Can you hear me?’ ‘Yes, I can.’ (= Yes, I can hear you.’)
- ‘Who broke the window?’ ‘John, did.’ (= John broke the window.)
To form the tag question
The anomalous finites are also used in the formation of the tag question.
- It is rather hot today, isn’t it?
- She can sing very well, can’t she?
- You like this color, don’t you?
- They shouldn’t have waited, should they?
When the statement is in the positive, the tag question is in the negative. In the same way, when the statement is in the negative, the tag question is in the positive.
To emphasize an affirmative statement
We can emphasize an affirmative statement by putting the anomalous finite do or its forms before the principal verb.
- I want you to come. (Less emphatic)
- I do want you to come. (More emphatic)
- I invited him. I did invite him.
- If another World War does break out, it will put an end to our civilization.