"In this sentence, what does 'back' mean?" "Back" in this case, means "again" more or less. It's a bit hard to explain, but it's like saying, "Would you rather have your old boss again?"

You could change your privacy settings to allow messages only from people you're following. That way, if you're only following women, only women could send you messages. Otherwise, there's the "delete" message option. The privacy settings on the site probably still need some work.

The mayor's office is in City Hall usually - if that's what you're asking. Not all cities have one, though.

Casablanca is a classic love story and a great movie.

Merhaba! FDMaxey is correct; however, "swag" also has a different meaning to younger people now. Currently, "swag" can refer to a flashy way of dressing, or just mean something is cool. Here is a humorous explanation of it: http://gawker.com/5804708/the-old-persons-guide-to-swag. Please, don't use it though! It sounds a bit silly ;)

I'm not sure what you're trying to say with "take it glasses." Something is lost in the translation there. As far as "being useful." The idiom is "come in handy." So, for example: "Take this screwdriver with you. It might come in handy." "I will keep this bottle with me. It might come in handy."

Take out "to you." "If" should be in lower case. The comma should come after "time." "Maybe if I have some time, I'll come by tomorrow."

I'm not certain that I understand the question completely. First Person Singular = "I am" First Person Plural = "We are" Second Person Singular or Plural = "You are" Third Person Masculine Singular = "He is" Third Person Feminine Singular = "She is" Third Person Neuter Singular = "It is" Third Person Plural = "They are" Does this answer your question? Or did I misunderstand it?