We use the past simple to talk about finished actions in the past. For example: I worked late yesterday. She called the client this morning. They finished the project last week.

For regular verbs, we add -ed: work → worked, finish → finished, start → started, decide → decided.

Some verbs are irregular and change completely: go → went, have → had, say → said, make → made, come → came, take → took, buy → bought.

For negatives, we use did not (didn't): I didn't go to the meeting. She didn't finish the report.

For questions, we use did: Did you speak to the manager? Did they send the email?