in, on, at, by
- in a period
in the ninetieth century
in
1993
in
Spring / Summer / Winter / Autumn
in
September / May
in
the morning / the afternoon
- on a day
on October 20th
on
Christmas Day / Valentine’s Day
on
Sunday
on
Saturday evening
- at a time
at ten o’clock
at
weekends
at
noon
at
midnight
- by a time
by 6 a.m. (at that time or before it)
- Exceptions
at night
at Christmas / at Easter (the period generally, not the day only)
on the morning / afternoon / evening of a certain date:
The explosion took place on the morning of the 20th.
- Phrases:
on time = at the time arranged
in time = not late

at, by, from, in, on, to
- We travel from our starting point to our destination.
- We travel by bus / car / train / boat / sea / plane / air /
bicycle.
- We travel on horseback, on foot, on a bicycle.
- We arrive in a country or town.
- We arrive at a village / an address / a hotel / a theatre / a
station / a bus stop / a cross-roads

- at + phrases
at all
at first
at last
at least
at random
at the beginning of the book / page / performance / course / meal /
tunnel / unit
at the front / back of the book / queue / plane
at the top / bottom of the mountain / list / ladder /page
- by + phrases
by far
by heart
by the way
- in + phrases
in all
in tears
in the middle of the corridor / book / queue / list / plane / row /
performance / course / meal / unit / ladder / tunnel
in the way
in time
- on + phrases
on average
on earth
on holiday
on the way
on time

Adjectives :: Adverbs ::
After, Before, When, While :: And, But ::
Articles :: Because of / Because :: Comparisons ::
Demonstratives :: Future ::
Irregular verbs :: Modals ::
Nouns :: Past Continuous ::
Past Simple :: Possessives :: Prepositions :: Present Continuous ::
Present Simple ::
Pronouns :: Quantifiers ::
Relative clauses :: Wh-Determiners
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