STRUCTURE
AUXILIAR FOR PRESENT PERFECT
HAVE & HAS
ADVERB FOR NEGATIVE EXPRESSIONS
YET
FORMS OF VERBS
PAST PARTICIPLE
GRAMMAR FORM FOR NEGATIVE EXPRESSIONS
SUBJECT+AUXILIAR NEGATIVE+VERB PAST PARTICIPLE+COMPLEMENT
ADVERBS FOR POSITIVE EXPRESSIONS
JUST & ALREADY
PAST PARTICIPLE OF DO
DONE
GRAMMAR FORM OF POSITIVE EXPRESSIONS
SUBJECT+AUX+VERB PAST PARTICIPLE+COMPLEMENT
I/GO/NEW YORK/YET
I HAVEN'T GONE TO NEW YORK YET
PAST PARTICIPLE OF TEACH
TAUGHT
FUNCTION OF PRESENT PERFECT
EXPRESSES EXPERIENCES
SAM/BE/IN MY HOUSE/ ALREADY
SAM HASN'T ALREADY BEEN IN MY HOUSE.
DIFFERENCE BETWEEN SIMPLE PAST AND PAST PARTICIPLE OF REGULAR VERBS
THERE IS NOT DIFFERENCE IN THE STRUCTURE