Prepositions

Prepositions show time,direction and many other functions.

Example: We will go to Sabah on Monday. We'll go by plane.

Prepositions are usually single words, but there are some prepositions which have more than one word

Example:We walked in between them.

Prepositions can be used before or after nouns, or with verbs and adjectives.

Common expressions using prepositions.

1) Use at before a certain place (At the market, At school)
2) Use in for a country or a town (In Shah Alam, In Sydey)
3) Use in for conditions (In pain, In sorrow)
4) Use in for ways of writing. (In pencil, In pen)
5) Use by for something done by others. ( Report by Athirah)
6) Use by for means of transportation ( By car, by Taxi)


For clearer explanations, refer to table below

English	Usage	Example
on	days of the week	on Monday
in	months / seasons time of day year after a certain period of time (when?)	in August / in winter in the morning in 2006 in an hour
at	for night for weekend a certain point of time (when?)	at night at the weekend at half past nine
since	from a certain point of time (past till now)	since 1980
for	over a certain period of time (past till now)	for 2 years
ago	a certain time in the past	2 years ago
before	earlier than a certain point of time	before 2004
to	telling the time	ten to six (5:50)
past	telling the time	ten past six (6:10)
to / till / until	marking the beginning and end of a period of time	from Monday to/till Friday
till / until	in the sense of how long something is going to last	He is on holiday until Friday.
by	in the sense of at the latest up to a certain time	I will be back by 6 o’clock. By 11 o'clock, I had read five pages.

http://www.ego4u.com/en/cram-up/grammar/prepositions