Posted by R. Berg on August 06, 2003
In Reply to: Prepositions posted by sphinx on August 06, 2003
: when speaking of time, I often find using prepositions very difficult. i've heard these ways of saying:
: on 21st, August
: on any given morning
: on the first night
: but I also know that:
: in the evening
: at night
: is correct.
: could you summarize its usage?
: thanks a lot!
The phrases in your first group of examples, the ones with "on," would be used to place an event at a particular time. John had a party ON his birthday. The employees get paid ON Fridays.
"In the evening" and "at night" describe the general kind of time when something happens, not the particular day or moment. (It is general in that every 24-hour period has an evening and a night.) John always eats dinner IN the evening. The employees work AT night.
But this distinction is subtle, and there are many exceptions. Words used with time designations in English are rather arbitrary.
These are some correct examples of usage:
The committee meets at 2:30 P.M. on Wednesdays.
Susan gets up early in the morning.
On that morning, Susan got up early.
Susan took a vacation in July.
Susan got a job in 2001.
(It's always "in" with months or years.)