Prepositions of place

The common place prepositions are: at, on and in.

I met him at the library.
He stood at the gate/door.
He sat at the table.
She put the basket on the table.
The cat is on the roof.
The lion is in the cage.
I live in Mumbai.

At can be used before specific addresses.

Are you still at the same address?

On can be used before streets, roads, avenues etc.

He lives on MG Road.

In is used before the names of large land areas such as cities, big towns, countries, states, continents etc. At is used before the names of small land-areas.

Compare:

She is in the US.
She is at the library.

Prepositions of Time

Common time prepositions are on, in and at.

At is used for a point of time, mainly clock time.

We will meet you at 5 o’ clock.
The meeting began at 2 am.

At can be used for holiday periods (e.g. at Christmas, at Easter, at Thanksgiving etc.). It is also used before time phrases such as at night, at that time, at an early date etc.

On is used for days and dates. Examples are: on Sunday, on second October, or on October second. In is used with the names of months and years. It can also be used with morning, afternoon and evening.

He was born in January.
He was born on a Wednesday.
He was born on 18th October.
I get up early in the morning.

The prepositions for, from and during indicate duration.

I worked here for two years.
I stayed there from May to July.
The sun shines during the day.

The prepositions before, after, since, until/till etc. are used with points of time.

He left home before 9 am.
I have been waiting since morning.
We waited till he returns.

Some other time prepositions are: between, by, up to, through, towards etc.

The meeting will be held between 4 am and 6 am.
By that time they were fully exhausted.
He worked through the night.
It is five minutes to ten.