Verbs are called perfect to indicate that they have perfective aspect.
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:
| Person | Present Perfect | Past Perfect | Future Perfect |
|---|---|---|---|
| I | have walked | had walked | will have walked |
| You (singular) | have walked | had walked | will have walked |
| He/She/It | has walked | had walked | will have walked |
| We | have walked | had walked | will have walked |
| You (plural) | have walked | had walked | will have walked |
| They | have walked | had walked | will have walked |
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.
Betty taught for ten years. (simple past)
Betty has taught for ten years. (present perfect)
Greek: See here.
Hebrew: These are called QTL forms; see here.