A question that comes up regularly in French conversations is:
Qu’est-ce que tu en penses?
What do you think (about that)?
For example, maybe a friend has planned a travel itinerary for her trip to Europe and wants your opinion on it: Qu’est-ce que tu en penses?
You’ll often hear an informal way of asking this same question:
Qu’est-ce t’en penses?
It sounds like “kess t’en penses.”
When this informal form occurs, you hear the question asked with qu’est-ce (sounds like “kess”) instead of qu’est-ce que (“kess que”).
T’en is a contraction of tu en.