PRESENT PERFECT TENSE

=> Present perfect tense is used to express action or situation that has or has occurred.When did the act or situation is not too important.

Present perfect tense sentence pattern:

Pattern I
(+) S + have / has + V3
(-) S + have / has + not + V3
(?) Have / has + S + V3

Pattern II
(+) S + have / has + been + adj / Adv / N
(-) S + have / has + not + been + adj / Adv / N
(?) Have / has + S + been + adj / Adv / N