This is part of a series of notes I'm taking as I learn Japanese. While learning you are constantly improving, but when you're experienced you forget what it was like to get there. I'm writing down those thoughts so fluent future me can know the idiot who created him.

I had been studying for 1 year and 4 months when I posted this.

Please sir, may I have some も?

I know of two meanings of も, both of which are somewhat related. In both cases, you’ve got some and you want a bit も.

Inclusive も / Also

You put it on the end of something to include it in the group of what you’re talking about.

私もいく

I’ll go too:
「私」(I) +「も」(include) +「いく」(go)

Literally, "I also go". In this case you’re including yourself in the group that is planning to go somewhere. This group would have come up earlier in the conversation.

ビールもワインも大好きです

I like beer, wine, etc:
「ビール」(beer) +「も」(include) +「ワイン」(wine) +「も」(include) +「大好き」(big like) +「です」(statement)

This one has も take a function similar to ‘etc.’ but it’s used on the items themselves instead of just thrown in at the end. It gives the impression that your love doesn’t end with only beer and wine, and that you may have a drinking problem.

Extensive も / Any

This version extends something to all of the thing, with emphasis on the non-specific-ness rather than the quantity. It’s not exactly pluralizing, because you’re not talking about many of thing. It’s more like any of thing; no specific one, but speaking of them all as a pool where the specific one you’re interested in resides.

何も

Anything:
「何」(what) +「も」(extend)

Literally 'any what’. There is a what but no particular what. It could be anything.

誰も

Anyone:
「誰」(who) +「も」(extend)

Literally 'any who’. There is an unknown person but no particular person. It could be anyone.

いつまでも

Forever:
「いつ」(when) +「まで」(until) +「も」(extend)

When with no particular end. Potentially forever.