Ravenclaw Dorm

Oh hello smarties! Its me, Merille and I'm your prefect for Ravenclaw!

Take a sip of tea or lemonade!

WIZARDS OR WITCHES THAT ARE NOT RAVENCLAW ARE NOT ALLOWED!

Ah yes and a riddle for you!

What is so fragile that saying its name breaks it? 

Oh message me the answer please!
- Merille