to indicate a time
A
to indicate a month, a year
en
To indicate the origin of a situation which lasts
depuis
To place an event in the past (in relation to the present moment)
il y a
To indicate a duration in its entirety
pendant
To place an event in the future (relative to the present moment)
dans
To mark a starting point
a partir de
To indicate the moment / event which causes / allows the occurrence of an action
des
To mark a time limit
jusqu’a
To indicate a planned duration (trip, contract)
pour
To mark the succession of facts
D’abbord,ensuite, puis, enfin