English uses three principal forms of the past, the Simple Past (or preterite), the Present Perfect, and the Past perfect.
- Simple past: This is used to relate past events in a historic context. Often, you will know that it must be used, because the sentence also contains an adverb (or adverb phrase) of time, such as yesterday, or a date or time.
- Present Perfect: In British English, this is used to situate past events, or the consequences of past events, in relation to the present situation. (that’s why we call it the “present” perfect). Americans do not always use the present perfect in this situation.
- Past perfect: is normally only used in English when one past event (either a specific action, or a contuous condition) has to be situated in a more distant past than another past event. In some situations, the progressive or continuous form is necessary.