What month of the year has 28 days?

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

What Word am I Looking For ?

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

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?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

Which Burger Is Different in below image?

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

The dirtier I get, the whiter I look. Who am I?

I am dry when I go inside, but wet when I am pulled outside.
The longer I am inside, the stronger I get
When I am completely out, I am wet and I literally sag
Who am I?

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?