But it really depends on what part of speech the pronoun is. The easiest, most foolproof way to figure out whether to use me or I is to drop the other person and see what sounds right. You would never say, "He gave it to I," so it's never "He gave it to mother and I." Whereas you absolutely would say "I went to the park" and not "Me went to the park." (Unless you're Cookie Monster.)
no subject
But it really depends on what part of speech the pronoun is. The easiest, most foolproof way to figure out whether to use me or I is to drop the other person and see what sounds right. You would never say, "He gave it to I," so it's never "He gave it to mother and I." Whereas you absolutely would say "I went to the park" and not "Me went to the park." (Unless you're Cookie Monster.)
It's "and [other person]" that confuses people!