I often say that the most underutilized word French learners should add to their vocabulary is ça.
Yes, the simple word ça.
Here are some examples of how ça is used.
Ça ne me dit rien
It’s not familiar
Ça te dit?
You feel like it?
Comment ça?
How come?
C’est ça!
That’s right!
C’est en plein ça!
That’s damn right! (in Quebec)
Comment ça se passe?
How is it going?