Firstly, the correct spelling would be " что бы то нИ было". The colloquial expression что бы то ни было means anything: to teach anything including Russian.

Hi Arnaud! Just to add, it is considered to be an adverb, and it has a subjunctive particle embedded - "бы". It can be roughly translated as "would". As a whole, it is something like "whatever", "anything", and such. Cheers!

To teach anything, including Russian language

Thanks a lot, you're explantation has really shed some new light on the problem for me. Unfortunately, english is richer than french on that particular subject, the "-ever" part of words like whatever, wherever, etc doesn't exist in french, that's part of my problem. We only have quiconque/quelconque for whoever/whatever and all the rest is rendered by words order and the subjonctive tense (wherever= où que ce soit/où qu'il soit for exemple) Another problem is that in french textbooks you learn that никто=nobody, ничего=nothing, нигде=nowhere, etc and that ни....ни (neither...nor) is also ni...ni in french, so basically you only learn that ни is "no" or something negative and that's all. Your exemples with что-НИбудь is really telling me something else on that aspect.

Somehow this "even"-meaning is associated with ни. Not in 'что-нибудь': here it is just indifference to the outcome: "Дай мне что-нибудь" = "give me ANY thing", whatever you like to give. But: "Дай мне хоть что-нибудь" = "give me at least some thing". Compare also: никто, никуда etc. E.g. "никто не думает" like "who-ever [we may take as an example, he] doesn't think". "никуда не пойду" which-ever-destination, not a single destination. ни ты ни я не.... neither you nor me... think of you, or think of me, result is the same: we both don't...