What is so fragile that saying its name breaks it?

While house hunting in London, I came across a very good leasehold property Discussing the lease the landlady told me:

'The property was originally on a 99 years lease and two-thirds of the time passed is equal to four-fifths of the time to come. Now work it out for yourself and see how many years are to go!

When does a USA Potato change its nationality?

Jessica is telling her friends this story and asks them to guess if it’s the truth or a lie: “There was a man sitting in a house at night that had no lights on at all. There was no lamp, no candle, and no other source of light. Yet, he sat in the house and read his book happily.” Her friends say she’s lying, but Jessica corrects them and says she’s telling the truth. Jessica’s story is true—but how?

If I put in one bird per cage, I have one bird too many. If I put in two bird per cage, I have one cage too many. How many cages and birds do I have?

How can you spell "White of an egg" in one word?
Hint: I know you can spell coke, poke, and joke.

Solve the equation by replacing the alphabet with numbers.

MOM + MOM + NO = BOOK=

What is the Surname of Barbie Doll?

If 21x = 79x, what is the value of x?

Buy me, smell me or deliver me, I do not change.

Who am I?