It depends if the phrase is subject or the object of a sentence. if it is a subject, the correct term is "she and you," as in "She and you went to the park"if it is an object, the correct term is...
any time a pronoun follows a preposition ("I" and "me" are pronouns, "for" is a prep.) it is in the objective case because it is the object of the preposition. Objective case pronouns are: me, you,...
That depends on the context of the sentence in which you are using them.
If for example you are suggesting that you and another should go somewhere, the correct use would be "you and I." As...
It depends on how they are used in a sentence. When it is the subject, or doing something, you use 'I." Example: I went shopping this morning. When it is an object, or someone is doing or giving...