- If I knew English, I should be able to read these English books.
假如我懂英语，我就能读这些英语书了。
- How well do you know English?
你的英语程度如何？
- If she had known English, she might have translated this book.
如果她懂英语，可能早就把这本书翻译出来。
- He does not know English, to say nothing of German or French.
他不懂英文，更不要说德文和法文了。
