SURPRISE! Most of the languages of the Silk Road are Turkic (Ugaritic - of the same language family and similar to Turkish). Starting from China, which speaks Mandarin and all the dialects of Chinese, next in Xinjiang (the northwest Muslim territories of China) they speak Uighur, which is a Turkic language.
Then westward to Kazakhstan, where the non-Russians speak Kazakh, a Turkic language. Kyrgyzstan contains people who speak Kyrgyz, a Turkic language. To the west is Uzbekistan, where the language is Uzbek, a Turkic language. To its west is Turkmenistan, where the language is Turkmen, a Turkic language. To the west, across the Caspian Sea, is Azerbaijan, where the language is Azeri, a Turkic language. Then we have Georgian and Armenian, which are not Turkic. Finally, we have Turkish.
My wife speaks maybe 2500 words of Turkish, and we are hoping to put that Turkish to good use on this trip. We still don't know how close Uighur, Kyrgyz, and Uzbek are to Turkish, but a quick perusal of some of the phrase books and dictionaries shows a whole lot of similar words and similar grammar. We'll see.
There are six major language groups in this area: Turkic, Arabic, Persian, Hindu-Urdu, Chinese, and Russian. Generally, the Arabic starts at the border of Iran and Iraq and goes westward. East of that and south of the Turkic belt is the Persian belt. It includes Farsi (in Persia), Tajik, and some of the Afghan languages. East of that are the Hindu-Urdu languages, including some of the Afghan languages. North of all of this is the old Soviet Union, with Russian.
For our trip, I am trying to learn 250-500 words of Mandarin (while we are in China) and 250-500 words of Russian (for the Stans). Because of their history - the Stans mostly became independent in August or September 1991 - anyone in the Stans over 25 years old speaks native Russian. We are still trying to get a feel for how good the Mandarin is for the Uighurs in Xinjiang. Some tell us that everyone there speaks perfect Mandarin. Some tell us that the Mandarin there is so heavily accented that no one can understand it. We will see.
My wife is polishing up on her Turkish, and taking a few steps toward trying to learn Uighur/Uzbek (apparently the two languages are quite similar).
The great unknown is how many folks speak English in any of these areas.
To say hello in Arabic, say "A-salaam aleykum." To say hello in Turkish, say "A-salaam aleykum." To say hello in Persian, say "A -salaam aleykum." To say hello in Uzbek and Uighur, say "Salam aleykum."
To say thank you in Arabic, say "Shukran." To say thank you in Turkish, say "Teshekkur," which is another form of the Arabic word. To say thank you in Persian, say "Rakhmat." To say thank you in Uzbek/Uighur, say "Rakhmat," but "Teshekkur" in Uighur seems to mean thanks, so there.
One, two, three in all of the Turkic languages is very close to Bir, ikki, uch. Bread in most of these languages in Nan, at least a certain kind is called nan.
Of course, coffee, tea (chai) and chocolate are the same in every language. Shashlik and kibab are universally recognized in these areas.
However, most of the words are different, and isn't that the great joy of all of this.