A preposition is an official part of speech which expresses the relationship between the subject and the object in a sentence. In English, prepositions are usually used with nouns and pronouns, but they are also used with verbs.
In / Into
The key difference between ‘in’ and ‘into’ is that ‘in’ indicates a state of being, whereas ‘into’ indicates motion. For example, ‘into’ is often used to describe the movement of something from outdoors to indoors, such as in the sentence, «I walked into the house.» By contrast, ‘in’ is used when a thing or person is stationary. For example, «I found the book in the drawer.»
Examples
Jack drove his car into the garage.
My friend lives in that house.
The teacher came quickly into the room and began the lesson.
The dishes are in that cupboard.
On / Onto
Similar to ‘into’ and ‘in’, ‘onto’ indicates motion where ‘on’ does not. ‘Onto’ normally indicates that something is placed onto something else. For example, «I put the dishes onto the table when I set it.» ‘On’ shows that something already rests on a surface. For example, «The picture is hanging on the wall.»
Examples
I carefully placed the picture onto the wall.
He put the book onto the desk.
You can find the dictionary on the table.
That’s a beautiful picture on the wall.
Among / Between
‘Among’ and ‘between’ are almost exactly the same in meaning. However, ‘between’ is used when something is placed between two objects. ‘Among’, on the other hand, is used when something is placed among many objects.
Examples
Tom is between Mary and Helen in that picture.
You’ll find the letter among the papers on the table.
Seattle is located between Vancouver, Canada, and Portland, Oregon.
Alice is among friends this weekend.
Beside / Besides
‘Beside’ – without an s- means ‘next to’. For example, «Tom is seated beside Alice.» In contrast, ‘Besides’ – with an ‘s’ – states that something is in addition to something else. For example, «Besides math, Peter is getting an A in history.»
Examples
Hang your coat beside mine over there.
There is so much work to do besides the normal tasks.
Come sit down beside me.
Besides potatoes, we need some milk.
Learn English Trough Games 