which
1
used to ask or talk about one or more members of a group of things or people, when we are not sure about it or about them
- Which of these options is the best solution to the problem?
- Which of these dresses do you like the most?
- Which restaurant did you go to for dinner last night?
- He asked me which route we should take to get to the airport.
- I can't remember which book I lent to Sarah.
2
used to refers to animals and things
- The car which is parked outside, belongs to John.
- The house which was built in the 19th century is now a museum.
- I bought a new smartphone which has a great camera.
3
used to represent a clause, idea, or concept that acts as the subject or object of the verb or preposition
- We need to decide which option to take.
- It's unclear which will be most effective.
Synonyms: