What is so fragile that saying its name breaks it?

A patient was diagnosed with some ailment. He was given five different tablets to take at night at an interval of 15 minutes.

How long will it take the patient to consume all the five tablets?

I am the black child of a white father, a wingless bird, flying even to the clouds of heaven. I give birth to tears of mourning in pupils that meet me, even though there is no cause for grief, and at once on my birth, I am dissolved into air. What am I?

There are two words one resembles the "state of rest" and the other is related to "writing/reading material".

Can you name these two words which also sound similar?

Which English verb becomes past tense just by rearranging the letters?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

Can you name some countries which do not have the alphabet 'A' in them?

If a boy blows 18 bubbles,
Then pops 6 eats 7 and then
He pops 5 and blows 1.
How many are left?

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

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