Was is the simple past tense. The negative form is was+not The simple past tense indicates the action or state at a certain moment in the past, and it can also indicate the action that happened frequently or repeatedly in the past. Often used with adverbial of past time.

simple past tense

1. Concept: an action or state that occurred at a certain time in the past; Habitual and regular actions and behaviors in the past.

2. adverbial of time: before, yesterday, the day before yesterday, last week, last (year, night, month …), at 1989, just now, 5 years old, a long time ago, once upon a time, etc.

3. Basic structure: be verb; Past tense of action verbs

4. Negative form: was/were+not; Add did before the action verb and restore the action verb at the same time.

5. General interrogative sentence: was or are put at the beginning of the sentence; Ask questions with the past tense did of the auxiliary verb do and restore the action verb at the same time.

She often helps us these days.

I didn't know you were so busy.

Step 7 use

(1) The simple past tense indicates the past action or state.

The simple past tense is usually used with adverbials of past time.

The adverbials of time used with the simple past tense are: yesterday, last night (week, year, month, day), then, that moment, just now, a few days ago (week, month, year) and so on. Example:

Lucy turned off all the lights before going out.

Lucy turned off all the lights before going out.