I would never learn jJapanese I would never learn Japanese

I think I'll never learn japanese. I think I'll never learn japanese.

Technically correct, but sounds odd. Alternative: "I don't think I'll ever learn Japanese."

I do like jthe Japanese language, but it's so different of ffrom French and the writing system is so difficult that I'm afraid to try to learn it. I do like the Japanese language, but it's so different from French and the writing system is so difficult that I'm afraid to try to learn it.

I have studied eEnglish for a long time and I am still not able to speak it fluently. I have studied English for a long time and I am still not able to speak it fluently.

As jJapanese seems more difficult to learn than eEnglish, I think it would take decades to speak a little jJapanese. As Japanese seems more difficult to learn than English, I think it would take decades to speak a little Japanese.