Problems viewed in this weeks' writing

Prepositions of Place: at, on, and in

We use at for specific addresses.
Grammar English lives at 55 Boretz Road in Durham.

We use on to designate names of streets, avenues, etc.
Her house is on Boretz Road.

And we use in for the names of land-areas (towns, counties, states, countries, and continents).
She lives in Durham.
Durham is in Windham County.
Windham County is in Connecticut.

Prepositions of Location: in, at, and on and No Preposition
IN (the) bed* the bedroom the car (the) class* the library* school*	AT class* home the library* the office school* work	ON the bed* the ceiling the floor the horse the plane the train	NO PREPOSITION downstairs downtown inside outside upstairs uptown
* You may sometimes use different prepositions for these locations.

Source     http://grammar.ccc.commnet.edu/grammar/prepositions.htm

Prepositions of Time: at, on, and in

We use at to designate specific times.
The train is due at 12:15 p.m.

We use on to designate days and dates.
My brother is coming on Monday.
We're having a party on the Fourth of July.

We use in for nonspecific times during a day, a month, a season, or a year.
She likes to jog in the morning.
It's too cold in winter to run outside.
He started the job in 1971.
He's going to quit in August.

Source     http://grammar.ccc.commnet.edu/grammar/prepositions.htm