Would Anyone Like Some?

We use some and any with plural or uncountable nouns to represent an unkown quantity. People often confuse when they should use any or some, so let's take a look.

Basically, we use some in affirmative phrases:

There are some people waiting for you.

And we use any in negative phrases:

There aren't any people waiting for you. 

(Paradoxically, we use no in affirmative phrases to indicate 0 quantity:

There are no people waiting for you.)

We also use any in questions: 

Is there any coffee in the kitchen?

Unless those questions are...

offers[1]: Would you like some coffee?

or requests[2]: Can I have some coffee, please?

On the other hand, we use any in affirmative phrases...

In if conditionals: If you need any help, call me.

Or when we don't care[3] about the result:

Come and visit me any time you want.

You can use some and any as pronouns:

I can't find any pens. Do you have any? Yes, there are some in my desk.

You can even combine some and any with other nouns or pronouns to form compound pronouns:

Would anyone like something to drink?

Does anybody understand what I'm talking about?!

[1] ofertas, [2] petición, [3] importar