何

1. Origins, structure, and basic meaning

• Structure: 何 (なに) is an interrogative pronoun asking about a thing or content. 何がありますか is direct; 何を持って行けばよいか is embedded.
• Basic usage: One asks what is on a desk; the other asks a teacher what should be brought.

2. Common pitfalls and similar expressions

• Subject queried in existence and object queried for action
  • The unknown in the existential sentence is 何が; the action object is 何を. Final か in the latter closes the embedded question.