Demystifying Spanish Grammar

Why does this word have an accent?When do I use ser and estar?Why por and not para?I don't understand the difference between the imperfect and the preterit.The subjunctive? I give up! Do these questions sound familiar to you? If they do you have the right book. I had the same exact questions when I was studying Spanish. Now I know them well enough to explain in this book. I have to admit that I don't always know the reason why I use one form instead of another; I learned a lot just from reading and listening to spoken Spanish.