Form:

• HAVE / HAS + past participle

Use:

• to talk about the present result of a past action
• period of time up to the present
• it describes the indefinite past (=/= Simple past)
• often used to describe personal experience
• used with EVER / NEVER and HOW LONG?
• not used with past time words
• used with FOR and SINCE when something started in the past and is continuing now
  • FOR + Simple past (action finished)
  • FOR + Present perfect (action continues)
  • SINCE: Present perfect only
• used with JUST, YET and ALREADY
• Present perfect can refer to:
  • unfinished past
  • indefinite past

• HAVE / HAS + BEEN + V-ing

Use:

• an action over a period of time up to now
• frequently used with HOW LONG?, FOR and SINCE
• to describe activities ending just before the present
• not used with verbs that cannot take the progressive

Present perfect simple:

• action complete
• final achievement important

Present perfect continuous:

• activity important
• achievement not important

Form:

• HAD + past participle

Use:

• to describe a time before the past time which is being discussed
• to describe a period of time leading to the past time which is being discussed
• often combined with the simple past

Form:

• HAD + BEEN + V-ing

Use:

• for an action over a period of time up to a past time
• not used with verbs that cannot take the progressive