more on preposition please!

[bagwis23]

i'm still confuse on(or in?) preposition....how about preposition of place and names etc....is it right to say - in time or on time, in USA or on USA?...can i have some easy rules or tricks perhaps.. coz i am really doubtful on(or in?) my prepositions(sigh)..tnx in advance

[Tdol]

On time- at the correct time
In time- almost late, but not
In the USA

[Jerry_ma]

Originally Posted by bagwis23

i'm still confuse on(or in?) preposition....how about preposition of place and names etc....is it right to say - in time or on time, in USA or on USA?...can i have some easy rules or tricks perhaps.. coz i am really doubtful on(or in?) my prepositions(sigh)..tnx in advance

I think it is better to say "confuse on preposition", and "doubtful on prepositions"
It's always not appropriate to say "on USA"