This is the 52nd most frequent Czech word.
což
The Czech word "což" means "which," "what," or "that," often used to introduce a relative clause or express a consequence.
The word 'což' is used here as a relative pronoun referring to the previous clause, indicating a cause-effect relationship.
Stalo se něco, což mě velmi překvapilo.
Something happened, which surprised me a lot.
In this context, 'což' acts as a linking word to introduce a contrast with the earlier statement.
Řekl jsi, že to uděláš, což se nakonec nestalo.
You said you would do it, which in the end did not happen.
Here, 'což' is used as a relative pronoun to provide additional information about the trip.