This is the 2299th most frequent Catalan word.
faltar
"Faltar" means "to lack," "to miss," or "to be absent."
In this sentence, 'falten' is used to express something that is lacking or missing with reference to the object 'dos llibres'.
Em falten dos llibres per acabar la col·lecció.
I am missing two books to complete the collection.
Here, 'falta de' expresses the absence or lack of something, specifically 'proves'.
A falta de proves, no podem concloure res.
In the absence of evidence, we cannot conclude anything.
The phrase 'va faltar a' is used to indicate someone's absence from an expected event, like 'reunió'.