Prepositions aren’t necessary to make a sentence complete, but they are crucial in communicating anything beyond the noun and verb (as in, “I know.”) Prepositions are also misused quite often. Here are five rules to help you know when to use prepositions, adapted from grammarbook.com:
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 you get this?
Incorrect: Where did you get this at?
Correct: I will go later.
Incorrect:I will go later on.
Correct: Take your feet off the table.
Incorrect: Take your feet of of the table.
Correct: Look out the window.
Incorrect: 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 23rd. / 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.
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.
Post submitted by Michelle