Use the present perfect tense for actions and states that started in the past and continue up to and into the present time.

** Verbs in the present perfect tense take the helping verb has (singular) or have (plural).

              E.g. I have been living here for the last two years.

Use the present perfect for actions and states that happened a number of times in the past and may happen again in the future.

              E.g. I have heard that song several times on the radio.

Use the present perfect for something that happened at an unspecified time in the past.

              E.g. Anna has seen that movie already.