english perfect tense

In English, the perfect tense is any verb that uses the helping verbs “have”, “has”, or “had”. It has the nuance of completed action.
The present perfect is built using “have” or “has” as in:

I have run
you have run
she has run

The future perfect is built using “will have” as in:

I will have run
you will have run
she will have run

The past perfect is built using “had” as in:

I had run
you had run
she had run

The perfect tense is generally used to refer to action that is completed in the past but the effects of which continue on into the present.  more

Betty taught for ten years. (simple past)
Betty has taught for ten years. (present perfect)