All nationalities have different languages all around the world from Africanist scram to sounds monk in Tibet. Nowadays have many popular languages for example English.
In Europe all people from young to elder know how to say same simple phrases in English, but they are almost know nation languages. Modern word is going to speak only in one way, but should we learn not only English but own community. For example Ukraine we have the same situation. Our nationality have been assimilating since 17th to now. So, how are we defending? Since chailhood we were studying not only English but Ukrainian too and when we are getting older. People knows national and foreing at perfect.
As for ancient languages which they are missed according history. People whose nation for example is Aljyr forgot everything at all. In 20th they got independent but all population speaks france. Years are going and this nation discovered a lot of important goals about language. Modern person in 21th need to know more than two languages: native and English. Nowadays if you don’t know how to communicate with different people all around the world you can stay in suburbs on society.
To sum up my knowledge and experience I can say that from youngest to elder need to learn first of all your native language then English. Of course children say that they don’t need tradition and culture because all world is simle. In addition to it parents must teach children both languages but native must be at firs position.