To form the past simple of regular
verbs, add -ed to the infinitive.
When the infinitive ends in e add -d.
When the infinitive ends in y, the y
changes to i and then add -ed.
| Infinitive | Past simple |
| finish | finished |
| decide | decided |
| study | studied |
To form the negative past simple use didn't + infinitive.
To form a past simple question use did + infinitive.