13. If he didn't visit lessons regularly, he wouldn't make such progress.
14. If you have told me about it before I would have been in Moscow for a long already.
15. It's a pity she had already left. If you called before she would be still here.
16. If I knew French I would speak to her a long ago.
17. If I knew German, I would read Goethe in original.
18. If i lived next to you, I would call on more often.
19. She's fine. If she was sick, her brother would have told me about it yesterday.
20. If he didn't listen to his doctor's advices, he wouldn't get better so soon.