Можно сказать я его совсем не знаю.

Можно сказать я его совсем не знаю. Мне пришлось выучить английский, потому, что некоторые предметы в школе были на английском.

Результаты (английский) 1:

You can say I don't know. I had to learn English, because some subjects in school were English.

Результаты (английский) 2:

You could say I do not know him. I had to learn English, because some subjects in school were English.

Результаты (английский) 3:

You can say I just don't know. I had to learn English, because some items in the school were in English.