How do you know which to use:
en, dans, sur, and à
when saying something like "it is at the library" or "i'm going to the cafe"

I'm going to the café = Je vais au café

it is at the library = il est a la bibliotheque
            (accent above a)^                ^(accent above e)

Dans means in
À can be used if you are saying le salle à manger

Hello! i'm marianne and i'm from montpellier, france. here is a picture of my family. in the photo, they are my grandparents, my uncles and aunts, and my parents. they are in the garden at my grandparents' house. this is my grandmother's birthday on november 8 and we are all at home for this occasion. my grandmother is seventy-nine! my grandfather is older. he is eighty years old! my uncles and aunts are very nice and interesting. they are with my parents and my grandparents in the picture. i take the picture and that's why i'm not in the picture. i'm happy with my grandparents because my cousins are there when we're here and we talk and play together. it's fun to be with the family. my family is very good and active. i love my family! how is your family? do you have cousins and grandparents? where are they?