It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

I have teeth but i don't bite. Who Am I ?

I am the black child of a white father, a wingless bird, flying even to the clouds of heaven. I give birth to tears of mourning in pupils that meet me, even though there is no cause for grief, and at once on my birth, I am dissolved into air. What am I?

If Rajina's daughter is my daughter's mom, who am I to Rajina?

What is so fragile that saying its name breaks it?

Railroad Crossing, look out for the cars. Can you spell that, without any R's ?

Which of the following words don't belong in the group and why?
CORSET, COSTER, SECTOR, ESCORT, COURTS

You can see it everyday, But cannot touch it at will. What is it?

John leaves home and then he takes three right turns. John wants to return to home but he was scared of Jacob, who is wearing a mask.

What is John Situation ?

How can you leave a room with two legs and return with six legs?