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. Examples:
	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. I must have been asleep when this rule was taught...I think we all have this problem!