В пособии рассматриваются основные моменты английской грамматики: части речи имя существительное, имя прилагательное и наречие; видо-временные формы глагола; модальные глаголы; неличные формы глагола

A. An incomplete period may be indicated by today or this
morning/afternoon/evening/week/month/year/century etc.
Note that the present perfect can be used with this morning only up to about
one o’clock, with this afternoon up to about five o’clock and so on because
after that time they become completed periods and actions occurring in them
must be put into the simple past:
(at 11 a.m.) Tom has rung up three times this morning.
(at 2 p.m.) Tom rang up three times this morning.
(at 4 p.m.) I haven’t seen Tom this afternoon.
(at 6 p.m.) I didn’t see Tom this afternoon.
The present perfect used with an incomplete period of time implies that the
action happened or didn’t happen at some undefined time during this period:
Have you met Ann today? (at any time today)
But if we know that an action usually happens at a certain time of our
incomplete period we use the simple past tense. If my alarm clock normally
rings at 7 o’clock, I might say at breakfast:
My alarm clock didn’t ring this morning.


B. lately, recently used with the present perfect also indicate an incomplete
period of time and mean ‘at any time during the last week/month etc.’ Note
that both lately and recently are used in negative and interrogative sentences
but in affirmatives recently is generally used:
Has he been here lately/recently?
He hasn’t been here lately/recently.
but: He has been here recently.


C. The present perfect can be used similarly with ever, never, always,
occasionally, often, several times:
-Have you ever fallen off a horse?
-Yes, I’ve fallen off quite often/occasionally.


D. The present perfect used with for and since:
1. for is used to say how long something has lasted.
for used with the present perfect denotes a period of time extending into
the present:
We have lived in London for ten years. (and still live there)