1) Someone (or Somebody) has broken the window.
Someone = a person, but we don´t know who.
2) He has something in his mouth.
Something = a thing, but we don´t know what.
3) James lives somewhere near New York City.
Somewhere = in/to a place but we don´t where.
SOMEONE or SOMEBODY (People)
- There´s someone at the house door.
- There´s somebody in the office
- Is there anyone here?
- There´s nobody here.
SOMETHING / ANYTHING / NOTHING (things)
- Mary said something (I don´t know what she said).
- He was mad and he didn´t said anything.
- What did she say? Nothing.
ANYBODY vs. SOMETHING
- Did you meet anyone interesting in the party?
- She said something.
When we answer a question or when we use a negative phrase we use anything.