Problems with Prepositions

Rule 1

You may end a sentence with a preposition. Just do not use extra prepositions when the meaning is clear without them.

Correct:
That is something I cannot agree with.
That is something with which I cannot agree.

Correct:
Where did he go?

Incorrect:
Where did he go to?

Correct:
Where did you get this?

Incorrect:
Where did you get this at?

Correct:
I will go later.

Incorrect:
I will go later on.

Correct:
Take your shoes off the bed.

Incorrect:
Take your shoes off of the bed.

Correct:
You may look out the window.

Incorrect:
You may look out of the window.

Correct:
Cut it into small pieces.

Incorrect:
Cut it up into small pieces.

Rule 2

Use on with expressions that indicate the time of an occurrence.

Examples:
He was born on December 23.
We will arrive on the fourth.

Rule 3

Of should never be used in place of have.

Correct:
I should have done it.

Incorrect:
I should of done it.

Rule 4

Between refers to two. Among is used for three or more.

Examples:
Divide the candy between the two of you.
Divide the candy among the three of you.

Rule 5

The word like may be used as a preposition and in informal writing, as a conjunction. In formal writing, use as, as if, or as though rather than like as the conjunction.

Examples:
Prepositional usage
You look so much like your mother.
Conjunction usage
You look like you are angry.
OR
You look as if you are angry.