Theory:
1 The Mistake:
"Will you call me tomorrow"?
The Correction:
"Will you call me tomorrow?"
The Reason:
All punctuation must go inside the quotation marks.
2 The Mistake:
I went to the market, I needed some fruit.
The Corrections:
I went to the market; I needed some fruit.
I went to the market, because I needed some fruit.
The Reason:
Two independent clauses cannot be joined by only a comma. A semi colon is needed, or a comma and a conjunction.
3 The Mistake:
I was hungry so I ate a sandwich.
The Correction:
I was hungry, so I ate a sandwich.
The Reason:
When two independant clauses are joined, a comma and conjunction is needed.
4 The Mistake:
You're crazy!!!
The Correction:
You're crazy!
The Reason:
More than one exclamation mark should never be used.