Is Sign Language a universal language?

I think sign language uses letters and different spelling of words depending on your language. If your Spanish, you would spell hello as hola and spell it differently. So if you're American and use sign language saying hello to a Spanish person, they wouldn't understand. Am I confusing you? I am confusing myself. It's a good thought about what you said.People should learn sign language, though. Many people in this world is deaf.

I think that there are differences in sign languages, because the one that is frequently used in the United States is called "American Sign Language". Although there are probably gestures that mean the same across languages (much as there are certain words like "hello" which translate broadly), there are others which will probably leave the viewer puzzled.

It's a nice idea, though!

well,it is really an good idea!!
as far as i know,there are kinds of sign languages in world .they are different..
some times,the culture determine the sign language alike or different! in Arab country,noding you head means No or Not,but It means Ok or YES in Asian country!

Yes sign language, like all languages are different in different countries. Some signs are universal, but there are signs in American Sign Language that are different than signs in Signing Exact English. Both types of signs are predominately used in the US. I, however, do not know what signs are used in other countries.

What a great question! It would be fantastic if it were universal. I can imagine that it must be much easier to communicate with people from other cultures if both parties can sign, because many of the words are physically recognisable even if they are not done exactly the same way. I have a close relative who is totally deaf, and learned to spell on my hands when I was a small child. I've since discovered that even with just spelling there are differences in the way people do it.