Answer:
If you have it, you want to share it. If you share it, you don't have it.
What can answer in any language? What can speak without a mouth? What can sing without an ear?
Different lights do make me strange, thus into different sizes I will change
What can touch someone once and last them a life time?
What has three ways out and just one way in?
I am your mother's brother's only brother in law. Who am I?