Prepositions are used to locate something in time and space, modify a noun; or tell when or where or under what conditions something happened. The following are guidelines for using prepositions correctly. This covers many common situations.
Prepositions of Time: at, in, on
|At||at is for specific times||The exam is at 12:15 PM|
|In||in is for nonspecific times during a day/month/year.||The exam is in the morning|
|On||on for days and dates||The exam is on Monday.
The exam is on Christmas Day.
Prepositions of Place: at, in, on
|At||We use at for specific addresses.||I live at 50 Pong Lai Road.|
|In||We use in for the names of land-areas (towns, counties, states, countries, and continents).||I live in Taipei.|
|On||We use on for the names of streets, avenues, etc.||I live on Pong Lai Road.|
Prepositions for describing our work:
|at company’s||I work at Comtrend|
|in departments||in the marketing department, as a technical writer.|
|on projects||I am working on a new manual|