Present perfect is a form of work that is used to declare an
act or event that has been done and is still associated with the present.
Formula :
·
Verbal :
(+)
S + Have/Has + V3 + O
(-)
S + Have/Has + not + V3 + O
(?)
have/has + S + V3 + O
Example :
(+) I have finished my work
(-) I have not finished my homework.
(?) Have I finished my homework?
·
Nominal :
(+)
S + have/has + to be 3 (been) + non verb + O
(-)
S + have/has + not + to be 3 + non verb + O
(?)
have/has + S + to be 3 + non verb + O?
Example :
(+)
She has been here for 20 minutes.
(-)
She has not been here for 20 minutes.
(?)
Has she been here for 20 minutes?