Which (of two); which one (of two); -- used interrogatively and relatively.
- Used in indirect questions to introduce one alternative: We should find out whether the museum is open. See Usage Notes at doubt, if.
- Used to introduce alternative possibilities: Whether she wins or whether she loses, this is her last tournament.
- Either: He passed the test, whether by skill or luck.
- Archaic Which: "We came in full View of a great Island or Continent, (for we knew not whether)” ( Jonathan Swift).
- whether or no Regardless of circumstances.