I frequently hear this.
Problem:
The “at” in this question is unnecessary.
Explanation:
Any time that you see a sentence ending with a preposition, re-word it so that the preposition is not at the end. Trying this with the above question, we get, “At where are you?” With this re-wording, we see that “at” is unnecessary — because “where” implies “at”. Put another way, “where” is conceptually equivalent to “at” plus a location.
Solution:
“Where are you?”
I often see or hear this.
Problem:
The preposition “from” is missing.
Explanation:
High schools and colleges graduate people; people don’t graduate high schools and colleges.
I also believe that omission of the preposition “from” helps to prove my “Devolution toward Simpler” linguistic hypothesis. It is simpler to say “graduated” than to say “graduated from”.
Solution:
“He graduated from college last year.”
I saw this in a restaurant.
Problem:
“From” requires “to” (not a hyphen).
Explanation:
Use a hyphen when you want to show a range (e.g., “grades 9 – 12”). Use “to” when you have a phrase that begins with “from” (e.g., “from Cleveland to Seattle”)
Solution:
“From 9 a.m. to Noon”