I use the iPhone in English, but I save the names of my contacts in Russian. The problem is that they all appear now under (#).
Is there any way to fix that?
Unfortunately since your iPhone is set to the default language of English; your contacts in Russian will be sent straight to the # section of your contact listings. The reasons are that the Russian and English alphabets are not associative, and therefore you cannot file Russian characters under English ones. Even though it could make sense that character sounds in Russian could be relatively phonically associated with English ones; it doesn't make sense to program something that heavy into a mobile OS. I have Japanese contacts on my phone, and it is pushed to the # section as well. I'm sorry that I couldn't solve your dilemma, but there isn't a solution (yet).
I had a similar problem. Have several contacts in Serbian (cyrillic) others in English. I solved the problem by adding to each contact written in cyrillic new fields for phonetic spelling for the last and the first name.
I'm not sure when this feature is added. My iOS version is 10.3.2 and this might change in the future.
Assuming you already have many contacts with English first/last names, and say you want to add a Chinese-named contact in the list so that it is not arrange inside the "#" section.
All you need to do is scroll to the bottom when adding a contact->add field->"Phonetic first name" and "Phonetic last name"->type in the first/last name field properly. The phonetic fields will be filled in automatically.
When editing an old contact, you can type a whitespace after the existing first/last name to auto fill the phonetic fields. Removing the whitespace afterward might change the format of the phonetic fields but will not remove them.
For other languages, you might have to type in them manually. Then this contact will be ordered by its phonetic field but displayed in its original language.
For Russian, Japanese, and other languages whose alphabets don't sort "properly" in an English system on the iPhone, enter your Contacts' names phonetically. The phonetic spelling will be used for alphabetization.
If you simply want to correct the way Siri says the names (without affecting the way the name is sorted -- either in English or phonetic), then enter your Contacts' names using the Pronunciation field.
For details on how to add these fields and enter the info, see Josh Centers' article in TidBITS (and the comments thereto), Socializing Siri: Add Relationships, Teach Pronunciations, and More.
Sorting Japanese or Chinese is not only difficult—it’s an unsolved problem. This seems hard to believe if you are not familiar with the complexities of processing Japanese or Chinese digitally. But what is trivially easy in English is impossible in Japanese or Chinese, even with the amount of computer power we have available today.