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?

I know a country, If you remove the last alphabet of its name, it will become a part of your body. Do you name it?

A man and a dog were going down the street. The man rode, yet walked. What was the dog’s name?

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?

You can hear me, but you can't touch or see me.

What am I?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different.

How do you measure 45 minutes?

What can go through glass without breaking it?

What's the only room from which no one can enter or leave