What is so fragile that saying its name breaks it?

Today is John's birthday.
A year ago, John had five candles and he lit all the candles except the one at the last.
Now he is going to light all the candles.

How old is John Today?

(He is not five today.....)

Find the missing number in the image below.

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

I add 5 to 9 and get 2. The answer is correct, so what am I?

If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?

Can you spot what's wrong with the following sentence?

PETER WAS ANGRY AT
HIMSELF BECAUSE HE
ACCIDENTALLY LEFT THE
THE KEYS TO HIS CAR
AT HIS FRIEND'S HOUSE.

You are confined in a room and given two metal rods. Out of these two rods, one is magnet and the other is the iron rod. They look starkly similar. You don't have any other metal object in the room.

How will you decide which one of those is magnet?

How many cubic feet of dirt are in a hole of one foot deep, three feet long, and two feet wide?