This is the 8th most frequent French word.
que
"Que" means "that," "which," or "what," and is used as a relative pronoun or conjunction in French.
In this sentence, 'que' is used as a conjunction to introduce a subordinate clause meaning 'that'.
Je pense que tu as raison.
I think that you are right.
Here, 'que' functions as a relative pronoun replacing the object of the relative clause.
C'est le livre que j'aime le plus.
This is the book that I like the most.
In this case, 'que' is an interrogative pronoun used to introduce a question meaning 'what'.