1.
If I know English, I will enjoy Byron's poetry.
If I knew English, I would enjoy Byron's poetry.
If I had known English, I would have enjoyed Byron's poetry.
2.
I'll be delighted if I have such a beautiful fur-coat.
I would be delighted if I had such a beautiful fur-coat.
I would have been delighted if I had had such a beautiful fur-coat.
3.
If he doesn't read so much, he will not be so clever.
If he didn't read so much, he wouldn't be so clever.
If he had not read so much, he would not have been so clever.
4.
We will stay at home if you don't get tickets for the Philharmonic.
We would stay at home if you didn't get tickets for the Philharmonic.
We would have stayed at home if you hadn't got tickets for the Philharmonic.
5.
You will consult the doctor if you are not so careless about your health.
You would consult the doctor if you weren't so careless about your health.
You would have consulted the doctor if you hadn't been so careless about your health.
Что тут конкретно надо сделать, если что