This is the 1881st most frequent Portuguese word.
tais
"Such" or "like those."
The word 'tais' is used as a pronoun referring to 'books', indicating their qualities.
Esses livros são tais que todos apreciam.
These books are such that everyone appreciates.
Here, 'tais' functions as an adjective describing 'problems', categorizing them as specific ones.
Qual seria a solução para tais problemas?
What would be the solution for such problems?
In this sentence, 'tais como' functions as a phrase introducing examples ('intelligence and empathy').