IN
in January
in 1978
in the twenties
Use 'in' a period of time in the future: (za jakiś czas)
in a few weeks
in a couple of days
AT
Use 'at' with precise time:
at six o'clock
at 10.30
at two p.m.
ON
Use 'on' with days of the week:
on Monday
on Fridays
Use 'on' with specific calendar days:
on Christmas day
on October 22nd
IMPORTANT NOTES
in the morning / afternoon / evening - at night
We say in the morning, afternoon or evening BUT we say 'at night'
FOR
Use 'for' with a period of time to express the duration or 'how long' something has happened:
for three weeks
for many years
WHILE
Use 'while' plus a verb form:
while I was watching TV
while I lived in New York
DURING
Use 'during' with a noun to express 'when' something happens:
during class
during my vacation
during the discussion
Last (w zeszłym..)
I went there last year.
What did you do last weekend?