Anyone, Anybody, No one, Nobody
The word '아무' is used to express the not choosing of any specific thing in the sense of "any" (e,g anything, anyone). Depending on the particle that follows it, it can either refer to people or things. To refer to people, the word 아무+나 is used to indicate "anyone" or "anybody", while 아무+도 is used to indicate "no one" or "nobody". Note that a negative expression must follow the use of 아무도.
1. While the 나 of 아무+(이)나 is also used with interrogative pronouns, such as in 누구+나，어디+나, 무엇+이나, and 언제+나 it sounds awkward to use the 도 of 아무+도with interrogative pronouns in the same way.
2. A positive expression must come after 아무+(이)나, while a negative expression must come after 아무十도.