Past, future and present perfect

We use the Past Simple for finished actions at a definite time in the past; regular verbs add -ed (work → worked, study → studied, stop → stopped) and irregular verbs change form (go → went, see → saw, buy → bought, take → took). In questions and negatives we use 'did' with the base verb (Did you go? I didn't go) and we use 'was/were' with the verb 'to be'. Common Past Simple markers are 'yesterday', 'ago', 'last week' and 'in 2010'. The Past Continuous (was/were + V-ing) describes an action in progress in the past, often a background action interrupted by a Past Simple action (I was reading when she called). For the future we use 'will' for predictions, promises and decisions made at the moment of speaking, but 'be going to' for plans, intentions and predictions based on present evidence. The Present Perfect (have/has + past participle) links the past to now: we use it for experiences (ever/never), for results we can see now, and for unfinished time, with markers such as 'just', 'already', 'yet', 'for', 'since' and 'recently'; we use 'for' with a period of time and 'since' with a starting point. For example: 'I have lived here since 2015' uses the Present Perfect because the action continues now, but 'I lived in Baku in 2015' uses the Past Simple because it is a finished time.