Answer:
I am clean when Iām black dirty when Iām white.
I am a portal to another world which you cannot enter. Only you can see me but I can't see you.
If you drop me I'm sure to crack. But give me a smile and I'll always smile back.
What gets bigger the more you take away?
I know a word of letters three. Add two and fewer there will be. What is the word?
What did the grape do when he got stepped on?