I love grammar tricks to help you figure out what word to use.
For example, who=he and whom=him. “Who is going to the party” can easily be restated “He is going to the party,” but it doesn’t work as “Him is going to the party.” Or you can do “For whom the bell tolls” as “For him the bell tolls.” (Sometimes you have to rearrange the sentence to make sense–”the bell tolls for him”–but the he/him thing still works.)
If you have trouble knowing when to use “me and him” or “he and I,” just drop one of the pronouns and see if the sentence still makes sense. “He and I went to the store” makes sense as either “I went to the store” or “He went to the store.” But “Him and me went to the store” doesn’t make sense as either “Him went to the store” or “Me went to the store.”
I just learned a new trick today. If you can put “by zombies” after a verb, it’s passive (generally a no-no in writing). For example: “I am being driven (by zombies) crazy” versus “Sue is driving (by zombies) me crazy.” The second sentence doesn’t work, therefore it’s not passive. The first, however, is passive.