Because "4A and C, C and D can't talk directly, B and C can talk directly; And "(2) three out of four people can speak a language", then "there are languages A, B and D"

And because "A can speak Japanese, D can't speak Japanese, and B can't speak English; Explain that all three people can only speak "French or Chinese"; Then there is "no one can speak Japanese and French at the same time", so this language can't be "French", only "Chinese".

In the end, "① A, B and C can speak two languages each, while D can only speak one language;

So there are: Japanese and China.

Ding-China people

C- English French 4A and C, C and D can't talk directly.

B- Chinese, French, B and C can talk directly, and B can't speak English.