Hi Sarah, that’s an excellent question! Sign language is not international. Almost every country has its own sign language. Some of them are closely related, like American and French, but they are still separate languages. American Sign Language and British Sign Language are actually nothing alike, but British is very close to Australian Sign Language (also called Auslan).

In Turkey, the sign language is called Türk ??aret Dili (TID) and in English it is called Turkish Sign Language. You can learn more about Turkish Sign Language at this website.

Also, you may have heard of something called Gestuno, or International Sign Language. This was created in 1973 and it is not frequently used; Gestuno is basically the sign language equivalent of Esperanto. There are a few speakers around the world but not many. You can read more about Gestuno here.

Also, just to add, even within the United States there is a difference between Signed English and American Sign Language so I wouldn’t doubt the presence of something completely different in Turkey

Well, as matter of fact, I was in Turkey two weeks ago. Despite many reports that many Deaf Americans came and never can find Deaf Turks, I did meet several Deaf Turkish people—was able to communicate with them in gestures but mostly thanks to a website where I did a quick study of signs in TID (Türk ??aret Dili) which helped me a lot… to show my SMALL knowledge of TID, the Deaf Turks were more willing to chat with me and reclairfy some of their signs taht I didn’t recall seeing on the website.
However—
The hearing Turks do have their own gestures—two index fingers putting together means: “you both are in love” or “girlfriend/boyfriend”.... a hand with flat out “O” means: “good” or “beautiful”... a hand putting on your heart/chest as you nod means: “No but thank you”... a nod-off with your head means: “No!”
As a Deaf American, it was easy to catch those subtle gestures by the general population of Turkey that my OWN professor (who have been lived in Turkey for 12 years!) oversaw!