1. SOMETHING, ANYTHING, NOTHING
something, somebody, someone
nothing, nobody, no one
anything, anybody, anyone

2. SOME V. ANY We use SOME in positive statements
There’s something in my shoe
We use ANY in negative statements and in questions
I can’t see anything
BUT we normally use SOME when we use a question to ask someone to do something
Would you like some blood, Mr. Dracula?

3. SOMEWHERE, ANYWHERE, NOWHERE
These words mean at/in/to some/any/no place so don’t put words like at/in/to in front of them!
I live somewhere (NOT `in somewhere’)
They’re going nowhere! (NOT `to nowhere’)

4. SPECIAL USES OF SOME/ANY/NO WORDS
Followed by an INFINITIVE
Have you got anything to do?
There’s no one to help you here
Followed by an ADJECTIVE
I want something really exciting
There’s nothing interesting in that room