PRESENT PERFECT

How do we make the Present Perfect Tense?

The structure of the present perfect tense is:

subject	+	auxiliary verb	+	main verb
		have		past participle

Here are some examples of the present perfect tense:

	subject	auxiliary verb		main verb
+	I	have		seen	ET.
+	You	have		eaten	mine.
-	She	has	not	been	to Rome.
-	We	have	not	played	football.
?	Have	you		finished?
?	Have	they		done	it?

Contractions with the present perfect tense

When we use the present perfect tense in speaking, we usually contract the subject and auxiliary verb. We also sometimes do this when we write. 

I have	I've
You have	You've
He has She has It has John has The car has	He's She's It's John's The car's
We have	We've
They have	They've

Here are some examples:

• I've finished my work.
• John's seen ET.
• They've gone home.

We often use for and since with the present perfect tense.

• We use for to talk about a period of time - 5 minutes, 2 weeks, 6 years.
• We use since to talk about a point in past time - 9 o'clock, 1st January, Monday.

for	since
a period of time	a point in past time
	x------------
20 minutes	6.15pm
three days	Monday
6 months	January
4 years	1994
2 centuries	1800
a long time	I left school
ever	the beginning of time
etc	etc

Here are some examples:

• I have been here for 20 minutes.
• I have been here since 9 o'clock.
• John hasn't called for 6 months.
• John hasn't called since February.
• He has worked in New York for a long time.
• He has worked in New York since he left school.

exercises

http://www.perfect-english-grammar.com/present-perfect-exercise-1.html

http://www.perfect-english-grammar.com/present-perfect-exercise-4.html

http://www.better-english.com/grammar/presentperfect1.htm

http://www.isabelperez.com/happy/tenses/exercises/present_perfect_1.htm

http://www.eclecticenglish.com/grammar/PresentPerfect1D.html