GRAMMAR :: Some and Any

Some ( = algo / algunos )

Use : In positive sentences. e.g.

I'm going to buy some clothes => Voy a comprar ropa.

We made some mistakes => Hicimos algunos errores.

We sometimes use some in interrogative sentences. 

Offers ( = Ofrecimientos ) => Would you like .......?  e.g. Would you like some coffee? 

Ask ( = Pedir ) => Can I have ....? e.g. Can I have some soup, please?

Any 

Use : In negative and interrogative sentences. e.g.

There isn't any milk in the fridge => No hay leche en la nevera.

Do you need any help? => ¿Necesitas ayuda?

Both of them can use alone too, without substantives. e.g.

I didn't take any photographs, but Jane took some.

You can have some coffee, but I don't want any.  

GRAMMAR :: Something / Anything / Nothing , etc

Something / Somebody or Someone / Somewhere

Use :  Positive sentences when you don't say exactly who, what or where.

Anything / Anybody or Anysomeone / Anywhere

Use : Negative and interrogative sentences.

In positive sentences meaning  =>

Anything => cualquier cosa / lo que sea.

Anybody or Anysomeone => cualquiera

Anywhere => en cualquier lugar.

Nothing / Nobody or Noone / Nowhere

Use : Negative meaning but positive verb. In short answers too.