The Present Perfect Tense

Opening

The Present Perfect Tense is almost the toughest tense for the learners of English though it is quite simple to get used to easily through practice as it is a very common tense in the language.

Use

This tense is used to show that an action is completed or 'perfected' by now. We use it to indicate that we are not interested in "when" the action started but rather on its completion and its effect. If we are interested in the time when the action began, the Past Simple would better be our tense. Therefore since the present state of completion of the action that interests us, we should use the present perfect.

Form

I	have	+ Past participle of the verb
You	have	+ Past participle of the verb
***********
He	has	+ Past participle of the verb
She	has	+ Past participle of the verb
It	has	+ Past participle of the verb
***********
We	have	+ Past participle of the verb
You	have	+ Past participle of the verb
They	have	+ Past participle of the verb

N.B: You need to learn your irreglar verbs for the past participle perfection.

Examples

Affirmative

I have seen that film. (when? that's not important here)
She has been there, too.
They have bought the house.

Negative

I haven't read the book yet.
He hasn't done his homework yet.
We haven't decided where to spend our holidays yet.

Interrogative

Have you finished yet?
Have you had your breakfast yet?
What has she done to her toys?
Have they been to the cinema?

Details

JUST & ALREADY

If we want to show that the action was completed a few minutes ago, we need to use the adverb "Just" as in:
I have Just finished eating.

On the contrary, if we want to show that the action was completed long ago and we don't want to talk or don't care about the time, we use the adverb "already" as in:

The boys have already come back from school.
He has fixed the car already.

FOR & SINCE

Contemplate

I have worked in that school for twenty years.
I have worked there since 1990.

As you notice:
FOR indicates the time passed since the beginning of the action.
So FOR is followed by a lapse/period of time; which could be 'one week', 'two months', 'seven years', 'ages', 'a long time', 'so long', etc.

SINCE indicates the starting point of an action that is still taking place.
Therefore SINCE is followed by a specific or vague time in the past; 'last week', 'last Monday', 'Saturday', 'primary school years', 'the dark ages' etc

Exercise       Fill in the blanks with FOR or SINCE:

They have been married a very long time.
I haven't met him January 2009.
She has been to France a decade.
He has eaten ten apples this morning.
I haven't seen the doctor two years.

Practice

Listening: Song

Listen to the song and write down the 4 sentences in the present perfect