What is so fragile that saying its name breaks it?

There are 2 cops parked along a one-way street looking for traffic violations. They spot a taxi driver going in the wrong direction, yet they do nothing.

Why?

A bus driver was heading down a street in Mexico. He went right past a stop sign without stopping, he turned left where there was a "no left turn" sign, and he went the wrong way on a one-way street. Then he went on the left side of the road past a cop car. Still - he didn't break any traffic laws. Why not?

There is something which is always coming but never arrives?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

How can you leave a room with two legs and return with six legs?

Jack and Joseph are well-known golf rivals. One Day during a match, they were level at a score of 30. Jack hit a bad shot and Joseph added 10 to his score. Joseph then hit an awesome shot and he won the game.

How ?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

It is always ahead of me yet I can never see it. What is it?

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