Introduction of "DID"

Simple Past: Negatives and Questions

In the simple past tense, negative and question forms are made using the auxiliary verb "do" (in its past form, "did") followed by the simple form of the main verb. This page explains the rules.

1. Forming a negative
Negatives in the simple present are formed by adding didn't (informal) or did not (formal) before the simple form of the verb. The verb BE is an exception to this; in the case of BE, we just add n't (informal) or not (formal) after "was" or "were":

e.g. I have a car. = I didn't have a car.

2. Forming a yes/no question
Yes/no questions are also created using the auxiliary did. This time, the auxiliary is placed before the subject. The verb BE is an exception; in this case, we move BE before the subject. Here are the rules:

e.g. They had a party. = Did they have a party?

3. Forming a WH- question
WH- questions (using words such as "what", "when", and "where") are also created by putting the auxiliary did before the subject (or moving BE, as explained above). Then, you add the WH- word at the beginning. Here are some examples:

e.g. He lives in Mexicali. = Did he live in Mexicali? = Where did he live?