A practical english grammar - Vyssaja skola 1978
Chapter 6 - The present perfect verb phrase
Sound symbols
The present perfect verb phrase consists of the present tense of the auxiliary verb have (have, has) and the past participle of the verb. In the case of regular verbs, the past participle has the same form as the past tense (worked, called). In the case of irregular verbs, it is a separate form that has to be learned for each verb, since it can not be predicted according to a rule (broken, told). The student will find these forms listed on pages 219-222.
The present perfect occurs in sentences like these:
I have called Mr. Adams twice this morning.
She has gone out.
Have you finished yet?
Hasn’t it stopped raining?
You will notice that the word-order pattern is the same as the one you have already become familiar with: n’t is attached to the auxiliary to form the negative, and questions are formed by putting the subject between the auxiliary and the verb.
Meaning of the present perfect. The essential meaning of the present perfect verb phrase is current relevance; that is, it mentions a past event (or condition) only because the importance or the effects of that event are still continuing to be felt. The present perfect must be carefully contrasted with the past tense, with which it is often confused.
She went out. (The event occurred at some time in the past; if it still affects the present situation, the verb phrase does not say so.)
She has gone out. (This event also occurred at some time in the past, but the important thing now is that she is not here; in other words, we are concerned with the results of her going out, not just the event itself.)
My grandfather went to Europe. (The event is past. Grandfather may not even still be living, since no current relevance is included in the verb phrase.)
My grandfather has gone to Europe. (Grandfather is certainly still alive, since this sentence could not reasonably be said of someone who had died. He is probably still in Europe. If not, the speaker means that Grandfather is now, at this moment, a person with the experience of having gone to Europe.)
Use of adverbs with the present perfect. Since the present perfect includes the present moment in its time span, it is easily understood that only those adverbs that include the present time can be used with it. Here are some adverbial expressions of this type.
now
today
this week (month, year, etc.)
since noon (or any other specific moment)
since you came (or any other such clause)
in my life; in his life (if he is still living) already
yet
until today (this week, etc.)
Time expressions that do not include the present moment, like yesterday, at 8 o’clock (in the past), at that time, then, must not be used with the present perfect. Study the following examples:
They have arrived now.
She has gone out today.
They have called several times this week.
I haven’t seen Mr. Black since noon.
I have never been to Tibet in my life.
That man has had many misfortunes in his life. (He is still living.)
Have they left already?
They haven’t left yet.
They left yesterday.
She called at 8 o’clock.
He had lots of good luck in his life. (He is dead.)
FOR and SINCE. Both of these prepositions introduce phrases that express time in English, but there is an important difference between them. For is always followed by an expression indicating an amount of time, while since is followed by an expression naming a point in time.
We have lived here for a year.
We have lived here since January.
I had not seen Jim since his arrival in the city.
It is not always necessary to use for in phrases indicating duration.
We have been here a week.
Since, in a present tense context, means “from (a certain moment) until now.” In a past tense context, it means “from (an earlier moment) until the time of interest.” Therefore it can be used only with the present perfect or the past perfect verb phrase. For, on the other hand, which merely expresses duration of time, can be used with any kind of verb or verb phrase.
We are living here for a month. (Now, temporarily.)
We live here for a month. (Regularly, every summer.)
We lived here for a month. (Last year.)
We have lived here for a month. (And are still living here.)