I read your most recent story, "Coffee Shop Mix-Up." A few mistakes but I didn't see any grammar issues to worry about and the syntax was clear enough (your specific questions). I don't know what the "mix-up" is in the story and the ending is lame--the one character has already graphically declared he's going to do what the other character asks for in the close-out line. So, the story ending could be stronger. That's not a problem of grammar or clarity, though.