Some, any, no

SOME- is used mostly in positive sentences: The translation is algo, alguien, algunos, en algún sitio, etc. Sometimes the word is not translated.

We bought some presents.
They've got some work to do
There's somebody standing by the window.
I'm hungry. I want something to eat.
I left it somewhere in this room.

ANY- is used mostly in in negatives and questions. It is not a good idea to think of one translation for ANY-, because depending on the context it will be translated as algo, alguien, etc. (usually in questions) OR nada, nadie, en ninguna parte, etc. (negatives). Sometimes it is not translated at all.

Notice that in sentences 1-5 ANY- is not a negative: it appears in negative sentences, it is used with a negative verb (or a negative word like never) and it is perhaps translated as nada, nadie, etc., BUT it's the verb that carries the negative element, not the word ANY-:

1.We didn't buy any presents.
2. They never do any work.
3.There isn't anyone standing by the window.
4.I don't want anything to eat.
5. I can't find it anywhere.

Did you buy any presents?
Do they do any work?
Is there anyone standing by the window?
Have you got anything made of wood?
Have you seen it anywhere?

There are three types of questions where SOME- is used:
Offers: Would you like some more milk?
Requests: Can I have some chocolate?
We expect the answer to be YES: Are you waiting for someone?


NO- carries a negative meaning too, so it cannot be used with isn't, aren't don't, never, etc. because you can't have two negatives in the same sentence. When you use NO-, the verb is positive.
They have no children = they haven't got any children.
There is no money in the box = there isn't any money in the box.
I said nothing = I didn't say anything.
They've got nowhere to live = they haven't got anywhere to live.


If the negative is in the subject, there is only one option:
Nobody came before six.         Anybody didn't come before six.


ANY- in positive sentences?
Yes, this is possible, but the meaning is completely different: cualquiera, cualquier cosa, en cualquier lugar, etc.
Anyone can do that. =Eso lo hace cualquiera.
Take any flowers you like! = Coge la flor que quieras.
It could be anywhere = Podría estar en cualquier parte.
What would you like to drink?  --Anything = Cualquier cosa. (=I would like to eat anything)


Compare the last sentence with:
What would you like to drink?  --Nothing   =Nada.


By the way, SOMEONE = SOMEBODY; ANYONE = ANYBODY, NO-ONE = NOBODY