simple past

1. regular verbs

1.1. affirmative

1.1.1. infinitive

1.1.1.1. +

1.1.1.1.1. ed

1.2. interrogative

1.2.1. did

1.2.1.1. +

1.2.1.1.1. NOT

1.3. negative

1.3.1. DID

1.3.1.1. +

1.3.1.1.1. SUBJECT

2. irregular verbs

2.1. affirmative

2.1.1. I bought AT SUPERMARKET

2.2. interrogative

2.2.1. I bought at the supermarket?

2.3. negative

2.3.1. I DID NOT BOUGTH AT THE SUPERMARKER

3. The simple past expresses an action in the past taking place once, never, several times. It can also be used for actions taking place one after another or in the middle of another action.