What work can one never finish?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

Can you find out the number that should replace the question mark with a valid reason?

What common phrase is represented by the below lines

Easy going:
Weak, 'I'm going.'
Tough, 'I'm staying.'

Medium going:
Weak, 'I'm going.'
Tough, 'I'm staying.'

Tough going:
Weak, 'I can't do it, I'm staying!'
Tough, 'Let's get going.'

What is the end of everything?

John went to a parrot shop in Mexico, and the parrot owner told him that his parrot is so unique that he repeats everything he hears. John got excited and immediately bought the parrot. John went home and spoke many words, but the parrot does not repeat anything.
He went again to the parrot shop and complaint to the shopkeeper, but the shopkeeper never lied. Explain?

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

The more of this there is, the less you see. What is it?

John can place six large boxes or nine small boxes into a carton.

Can you find out in how many cartons can he place sixty-six boxes in total?

Spelt forwards I’m what you do every day, spelled backwards I’m something you hate. What am I?