Hello Glakit ,Originally Posted by Glakit
This is a very common question and one that even native speakers confuse!
1. Mary and I went shopping is correct because "Mary and I" is the compound subject. You are doing the action.
2. "Me and Mary" or "Mary and me" are a compound object. You and Mary in this case would be receiving the action: John threw the ball to Mary and me.
3. Mom bought Mary and me some ice cream.
Does this clear it up for you?
Sweet Momma Sue