When do I use she and I and when do I use me and her?

4 answers

"She and I went to the movies"
if in doubt I say the sentence using only the first person singular:
"I went to the movies" - there is no way I could say: "Me went to the movies". Thus if it is "I", then it also has to be "she" (not "her")

"My mother went to the store with me and her." Could you say:
"My mother went to the store with I"?
No, of course not - therefore "me" goes together with "her".
Hope that helps!
Just a little clarification for the excellent examples E.G. gave you.

The first set "She and I" are subjects so the verb will reflect that. She went, I went, She and I went.

the second set "me and her" are objects. So they will come after a verb. Another example could me "He saw me and her." (the subject is "he" but the objects are "me/her."

Sra
yes she is totolly right you can say my mom went to the store me and her went to the store together

i wnt to the movies (is correct)
me went to the movies(doesnt make sence)
Jessica - I think you meant to say "me and her went to the store together" is INCORRECT.
As SraJMcGin explained so well (and I tried to explain in my simple way)it would be incorrect to say "me and her went to the store together"; it has to be: "she and I (or I and she) went to the store together."