There are a lot of common mistakes I find after years of editing student assignments.
You should EXPLAIN and analyze your quotes after you insert them into your papers. Also introduce the background, speaker, etc, don’t have quotes appear out of nowhere.
A better way to make quotes flow:
Sample Quote: “I didn’t have time to go to Safeway because I was too busy studying for the SATs at my friend’s house.”
This can be changed to: She said “[she] didn’t have time to go to Safeway because [she] was too busy studying . . . at [her] friend’s house.”
*use [ ] to substitute word(s)
*use . . . to skip words