Preposition is something tricky for everyone who learn English as second language, me included. I think the best way to understand how to use a correct preposition is by practicing, learning by doing, and by reading a lot so you have this familiarity of when to use which.

What are prepositions?

Prepositions are words to link a noun or a phrase to another part of the sentence. Some examples are "in", "at", "on", and "to".

When using a preposition, you must always have a subject and verb BEFORE it, and follow it with a noun.

Preposition of position

Including at, on, in, between, among, above, under, below, over, beneath, etc.

At is used to indicate an exact point

They are staying at Marriot Hotel

He studied at University of Belgrade

In is used to express larger areas

She lives in London

Between is used for two things

It is a secret between us

There is a big wall between northern and southern part of the country.

Among is use with more than two things

The disease spread quickly among the villagers.

She is disappeared among the crowd.

Above is used to indicate position higher than something

The plane is now above the cloud

The water is now above our knees.

Under is used to indicate position lower than something

Let's sit down under the tree.

I hid the money under the mattress.

Below is used to indicate position lower than something

You need to work harder, your point is below average.

I could see the clouds below the plane.

Over is used for a position at a higher level than something else

A bird flies over the lake.

A plane flew over the mountain.

Beneath is for lower position

The paper was hidden beneath the stack of books.

She wears a linen dress beneath her coat.

Preposition of time

Including at, in, on, etc.

At for precise time

Meet me at 3.30 tomorrow

He came home at dinnertime.

We need to leave at sunrise.

In for months, years, centuries, and long periods

She will come home in the summer.

There were dinosaurs in the past.

Cigarettes were really popular in the early 19th century.

On for days and dates

We are going to have family dinner on Sunday.

He was born on December 8th.

She was alone on Christmas Day.

There are still many example of prepositions which are not included in here. Put in the comment if you have more examples.