I learned some prepositns today. I basically understand the uses of some prepositions.
1. in, at , on when they express locations.
in: to express sb or sth locats inside of a location, not exact.
at: to express sb or sth locats a exact location.
on: to express sb or sth locats surface of a location.
Examples:
I just arrived at the train station.
I just arrived at a building of the train station.
I just arrived on a square of the train station.
2. until, till, before, by
untill's meaning equals till. to express the duration ofamovement; by expresses a movement completed last time.
Examples: I am going to work until( till) seven tonight.
I am going to complete work by seven tonight.
I am going to work before seven tonight.
