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 How many of you can I count on?
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.


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

Rule 3

0f 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

Into implies entrance, in does not.


Sally walked into the house.
Sally was waiting in the house.
Mindy came in to see me today.
In is part of the verb phrase came in while
to is part of to see.

Rule 6

The word like, when used to show comparison, is a preposition, meaning that it should be followed by an object of the preposition but not by a subject and verb. Use the connectors (also called conjunctions) as or as if when following a comparison with a subject and verb.


You look so much like your mother.
Mother is the object of the preposition like.
You look as if you are angry.
As if is connecting two pairs of subjects and verbs.

Other Grammar Pages:

  • Subjects and Verbs
  • Subject and Verb Agreement
  • Pronouns
  • Who and Whom
  • Whoever and Whomever
  • Who v Which v That
  • Adjectives and Adverbs
  • Confusing Words and Homonyms
  • Fragments
  • Capital Letters