Lý thuyết giới từ

PREPOSITIONS
1 - PREPOSITIONS OF TIME
9.1 Usage: At, On, In: These prepositions are used to show the time and date of events, activities and situations:
e.g. at three o`clock. in June. on Monday.
9.2 Structure: At:
at + particular time: dawn, midday, noon, night, midnight, nine o`clock etc.. e.g. at dawn.
at + the + a particular time in a week/month/year: start/end of the week/month/year, weekend. e.g. at the start of July.
at + calendar festival season: Christmas, New Year, Easter etc.. e.g. at Easter.
at + meal: breakfast, lunch, mid-morning, tea, dinner, supper etc.. e.g. at breakfast.
9.3 Structure: On:
on + day of the week: Monday, Tuesday, Wednesday etc. e.g. on Thursday.
on + particular part of a day: Friday morning, Saturday afternoon. e.g. on Sunday evening.
on + particular date: 25 July 2001, 4 January. e.g. on 19 March.
N.B. On the nineteenth of March is how this date is read aloud or said in conversation.
on + calendar festival day: Christmas Day, Palm Sunday. e.g. on Easter Sunday.
9.4 Structure: In:
in + the + a part of a day: the morning, the afternoon, evening. e.g. in the afternoon.
in + month: January, February, March, April, May etc.. e.g. in June.
in + season of the year: Spring, Summer, Autumn. e.g. in Winter.
in + specific year: 1988, 1989, 1990 etc.. e.g. in 1999.
in + the + a specific century: nineteenth century. e. g. in the twentieth century.
in + historical period of time: the Dark Ages, Pre-historic Times. e.g. in the Middle Ages.
N.B. No preposition is used if the day/year has each, every, last, next, this before it:
e.g. I go to England every Christmas ( not at every Christmas )
I`ll see you next Monday afternoon. ( not on Monday afternoon )
Martin left home last evening. ( not in the evening )
9.5 Usage: For and Since:
These prepositions explain how long an event, activity, situation has continued:
e.g. for three days since last Thursday
9.6 Structure: For:
for + a period of time: two days, one week, three months, four years e.g. for the weekend.
This phrase can be used with all verb tenses.
e.g. Michael went to Latvia last year for three weeks. - past
I am in Poznan for ten days. - present
My cousin will be visiting the West Indies for two months next February. - future
9.7 Structure: Since:
since + a point of time + past tense: last week, the war ended, 1990, yesterday.
The point of time does not have to be accurate.
e.g. My sister and her husband have worked in India since 1991.
Arek has been very ill since yesterday evening.
9.8 Usage: During and While:
These prepositions explain a period of time in which an event, activity or situation took place:
e.g. during the next month while I was swimming.
9.9 Structure: During:
during + a noun or phrase: the war, the nineteenth century: e.g. during my schooldays. This phrase can be used with all verb tenses: past, present, future.
e.g. Magda received many telephone messages during the last week. - past
I am seeing Simon during the morning. - present
Winston will return to England during the Christmas Holiday. - future
9.10 Structure: While:
while + subject + verb: to eat, talk, swim, walk etc.... This clause can be used with all verb tenses: past, present, future
e.g. We will take you to the theatre while we are in London.
While Joanna was in Spain, she didn`t go to a bull fight.
N.B. In English, While can often be replaced by when and retain the same meaning.
while + infinitive + -ing (Present Participle): thinking, running, driving etc..
 e.g. While swimming in the sea, Hania was attacked by a shark.
Ela met Andrew while studying English at Oxford.
9.11 Usage: Before and After:
These prepositions explain accurately the timing of an event, activity or situation