What has one letter and starts with an E?

John was piloting a plane behind a car but was never able to overtake it. Why?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

I have an eye but still cannot see.

Who am I?

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

1 rabbit saw 9 elephants while going to the river. Every elephant saw 3 monkeys going toward the river. Each monkey had 1 parrot in each hand. How many animals are going towards the river?

What is the riddle which can be asked all day with a different correct answer each time.

What month of the year has 28 days?