I wouldn’t have to be teaching you grammar if your grade school teacher had taught you properly. But that didn’t happen. She didn’t know. He didn’t know. So he/she/they just left you in muddle, where you are today.
Let’s unmuddle that muddle. Let’s learn about the compound me and you. Let’s learn about the problem that Sam always brings.
You know Sam. ‘Is it between Sam and me or between Sam and I?’ you ask. ‘How am I supposed to be able to tell? When I go walking with Sam, is it I or is it me with whom Sam is walking?’
See, that’s Sam. Always causing problems. You’re liable to accidentally wander into traffic with conundrums like that puzzling your head.
But problems like that can be solved.
First, you have to look at a list:
I, he, she, they, we and who.
Then another list:
Me, him, her, them, us and whom.
The words in the first list are all the same. They can interchange.
I went. She went. He went. They went. We went. Who went?
That’s the rule. They can interchange.
The words in the second list are all the same. They can interchange.
He went with me, with her, with him, with us, with them. And. With whom?
You can use this interchangeability, which should be pretty obvious already, to get around all those problems Sam is causing.
For instance, is it ‘between Sam and me’ or ‘between Sam and I’? Well, between ‘Sam and I’ is the same as ‘between we.’ I and we are on the same list of interchangeable forms. Does ‘between we’ sound right? Nope? So ‘between Sam and me’ (which translates as ‘between us’) is correct.
That’s the fusion method. Sam and me or Sam and I are fused together into a we or an us, as appropriate, and our grammar sense will tell us from there which one is right.
For true atomic grammar completeness, there is also the fission method. ‘Sam and me’ and ‘Sam and I’ are split apart. Sam is sent on his way for leading us into bad grammar.
Thus, when confronted with the question of which is correct, “He went to the store with Sam and I’ or ‘He went to the store with Sam and me’? you can use the fission method, send Sam home and go it alone. Does “He went to the store with I” sound correct? No? Therefore, ‘Sam and I’ is wrong and ‘Sam and me’ is correct.
There you go. Use atomic grammar, fission or fusion, and you need never question again who went to the store and with whom.
You can then go on to asking “Why am I here all alone? Is it this strange obsession with subject and object pronouns?”