Hi, Hadeer. In your case there is no difference between sentences because dream of and dream about can be replaced by the word imagine. (You will see something you can't imagine) dream ABOUT = (when you are asleep) e.g. I dreamt about you last night. dream OF or ABOUT being something /doing something =imagine e.g. Do you dream of (or about) being rich and famous? I wouldn't dream OF doing something = I would never do it e.g. Don't tell anyone what I said.' ~ No , I wouldn't dream of it.