Why is Saturday stronger than Monday?

I am written with two letters.
I said with the one.
I usually am seen with the two.

Who am I?

If six children and two dogs were under an umbrella, how come none of them got wet?

How many times can you subtract the number two from the number fifty?

Can you find the mistake in the below statement?

For an extra income, John decided to work at a Hotel for one hour daily. The manager offers him that they will pay him $11 after every 11 days.
However, John offered a different proposition to the manager. The offers stand as:
He will be paid just a penny on his first day.
Two pence will be paid on the second day,
Four pence will be paid on the third day.
And so on till the 11th day.

Should the Hotel manager accept his offer?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

A man was found murdered on Sunday morning. His wife immediately called the police. The police questioned the wife and staff and got these alibis: The Wife said she was sleeping. The Cook was cooking breakfast. The Gardener was picking vegetables. The Maid was getting the mail. The Butler was cleaning the closet. The police instantly arrested the murderer. Who did it and how did they know?

The more you take me, the more you leave me behind.
Who Am I?

There is an English word that can be used up to four times in a row without modifying the spelling and form a valid grammatical sentence.

Do you know what word is that?