| Tense | Key use | Signal words |
|---|---|---|
| Simple past | Completed action at a specific past time | yesterday, last night, ago, in 2010 |
| Past continuous | Action in progress at a past moment | when, while, at that moment |
| Past perfect | Action completed before another past action | by the time, already, after, before |
| Present perfect | Past action with present relevance; unfinished time | ever, never, already, yet, just, since, for |
| Present perfect continuous | Ongoing action started in the past — emphasises duration | for, since, how long, all day |
| Passive (past) | Action done to the subject at a past moment | was/were + past participle; by |