What has many keys but can’t open a single lock?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

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

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?

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

I make two people out of one. What am I?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?

What month of the year has 28 days?

I am a five-letter word and comprises two different vowels and three same consonants. I am so strong that I can spoil your entire work.

Can you find out who am I?