B) since, adverb

Note!

Note!

Main uses

Formation

Unit 7 The Present Perfect Tense

The present perfect tense is formed with the present tense of have + the past participle:

Affirmative: I've done my homework.

Negative: I haven't done my homework.

Interrogative: Have you done your homework?

Negative interrogative: has he not worked?

The present perfect tense is used to express:

1 A finished action that has a result or a consequence in the present,

the time of the action is not given:

I’ve lost my key (=I haven’t got it now - result). I can’t open the door. (consequence now).

I’ve baked a cake. You may taste it.

I have forgotten her name! (I don’t remember it now)

Though the action expressed in the Present Perfect is regarded as already accomplished, it belongs to the present-time sphere and is treated as a present action. It becomes obvious from the periphrasis:

I've heard the doctor's opinion I know the doctor's opinion.

She's gone off to the woods She is in the woods.

Note the use of the Past Indefinite with just now.

I told you just now I had never had time for much fun.

2 With just, already, yet, so far etc. to express а recently completed

action:

Не has just gone out. (Hе went out a few minutes ago.)

There have been some changes lately/recently.

He's had a lot of bad luck lately/recently.

Lately is less usual with the affirmative, except for actions covering periods of time

Recently, used with a simple past tense, means 'a short time ago':

He left recently = He left a short time ago.

3 To give news of recent events or to give new information:

a) The present perfect is often used in newspapers and broadcasts to introduce an action which will then be described in the simple past tense.

There has been an explosion at Attenborough castle.

The past tense will normally be used in the second sentence:

Two prisoners have escaped from Dartmoor. They used a ladder which had been left behind by some workmen, climbed a twenty-foot wall and got away in a stolen car.

There has been a plane crash near Bristol. The witnesses say that there was an explosion as the aircraft was taking off.

b) The present perfect is often used in letters:

I am sorry I haven't written before but I 've been very busy lately as Tom has been away.

We have carefully considered the report which you sent us on 26 April, and have decided to take the following action.

c) When we report that someone has recently invented, discovered, produced, written something:

Scientists have discovered a new physical phenomena.

Compare:

Chinese craftsmen invented both paper and printing. (distant past, past simple is used).

d) Present Perfect may also be used to sum up a situation.

"You've so often been helpful in the past." "I've tried," said Joseph.

"Agatha has told me everything. How cleverly you have both kept your secret,"

4 For past actions with a word or phrase denoting аn incomplete period

of time: today, this morning/week/month/year etc.:

(at 11 a.m.) Tom has rung up three times this morning already.

(morning ends about one o’clock):

(at 2 p.m.) Tom rang up three times this morning.

Similarly, this afternoon will end at about five o'clock:

(at 4 p.m.) I haven't seen Tom this afternoon.

(at 6 p.m.) I didn't see Tom this afternoon

5 To express personal experience with ever, never, so far, always,

occasionally, often, several times in my life, up to now etc. or to say that an action or event has been repeated a number of times up to now:

I've never ridden а horse in my life.

I’ve often wished I could read music

ANN: Have you ever fallen off a hone?

TOM: Yes, I've fallen off quite often/occasionally.

Note:

In this situation we use the present perfect to describe an action that can still happen, or could be repeated in the present. So, if Tom's riding days are over, we would have:

ANN: Did you ever fall off a horse? (past tense)

TOM: Yes, 1 did occasionally/frequently

Similarly, ‘ I have seen wolves in that forest’ implies that it is still possible to see them and ‘John Smith has written a number of short stories’ implies that John Smith is still alive and can write more.

If, however, the wolves have been killed off and John Smith is dead we would say: I saw wolves in that forest once/several times or I used to see wolves here. John Smith wrote a number of short stones.

6 The present perfect can be used with since:

a) since + a point in time:

She has been here since six o'clock, (and is still here)

We've been friends since our schooldays.

Note that there is a difference between last and the last.

Compare:

I have been here since last week (month, year etc.)

I have been here for the last week.

He had a bad fall last year and has been off work ever since (adverb)

c) since + clause,

I've worked here since I left school

She has seemed so much better since you started the injections.

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