When do we need to add the pronoun, for example 'me', 'se', etc before the verb?
When do we need to add the pronoun, for example 'me', 'se', etc before the verb? E.g. Celia se casa dentro de tres semanas
If the verb casar is already conjugated in the "ella" form to --> "casa", why do we still need to put "se" in front of the "casa"?
3 Answers
When I asked my Spanish profesor this question, she said that it is porbalby, "to confuse the gringo!" I'm absolutely certain she was joking. This is just one of those rules of the Spanish language that we must get accustomed to. It is to clarify that the action is being performed to or on behalf of "se," which could be he, she, it, or them.
If the verb casar is already conjugated in the "ella" form to --> "casa", why do we still need to put "se" in front of the "casa"?
If your verb is "casar" then you wouldn't need to. But the verb you are asking about is "casarse". Any Spanish verb that ends with 'se' must use the "me, te, se" when it is conjugated or it is not the same verb. That's part of conjugating it. 
One of my Spanish teachers explained that casa = marries and se casa = gets married. So I guess you could say "Celia casa a su novio." and that would be Celia marries her fiancé. Does this make sense?
