So much confusion around how to structure a sentence referencing multiple people. For example: "Me and John went to the shops."
(I don't know why I chose John. He's my brother. I don't think we've ever been shopping together.)
The key to this area of grammar lies in pronouns, such as I, he, we, you. Those are "subject" pronouns. Then there are "object" pronouns – me, him, us – and "possessive" pronouns – mine, theirs, his.
Where are you going? Come back!
I honestly do feel your pain – during the period when I was at secondary school, the education powers-that-be had decided not to teach students grammar, which has proved quite inconvenient for those of us who have gone on to work with language.
Fortunately, as a teen I read a lot of Victorian literature, which is brutal in its grammatical perfection. It's also the reason my sentences can be interminably long labyrinths. Lol.
I'm basically self-taught when it comes to understanding what is right and wrong, so I know instinctively if a sentence is badly constructed but can't really tell you why. Thank goodness for Ecosia*.
So – me and John went to the shops. This is incorrect because when referring to yourself and somebody else, you put their name first.
"John and me went to the shops." Wait! That's wrong, too!
This is when knowledge of grammatical terms would be useful. Where the pronoun in a sentence is the subject, you use a subject pronoun. In "John and me went to the shops", John and I (see what I did there?) are the subjects. The sentence is about us. So we need to use the subject pronoun "I", not the object pronoun "me".
I found that deleting the other subject from the sentence helps clarify things really quickly. So – delete John. (Not literally.) If you delete John, you have "me went to the shops."
That's clearly wrong.
On the other hand... "Mike bought John and I a drink." (Mike's my husband. He would totally buy the drinks, he's very generous.) We've used the subject "I" there but it doesn't sound right. That's because it isn't – in this sentence, John and I are the objects.
Say, "Mike bought I a drink." Nope. So, extrapolate from that and you have "Mike bought John and me a drink."
I cringe the most when I see/hear people using "myself" when they just mean I or me. "Myself and Katie went to the cinema," for example. It's easier and more acceptable, really, to make these mistakes in speech rather than writing, but I honestly don't think anyone says "myself went to the cinema".
I'm just glad my children are being taught grammar at school now.
*Ecosia is my go-to Google replacement.