Unfortunately, I don’t know Philosophy, so I can’t answer your question.
If I know Philosophy, I can answer your question.
If I know Philosophy, I will be able to answer your question.
If I knew Philosophy, I would be able to answer your question.
If I had known Philosophy, I would have been able to answer your question.
_____ there are some more ideas, we can end the meeting now.
A. If B. As if C. Unless D. In case
If he _____ with us now, he _____ the beauty of nature of the National Park.
A. is / can enjoy B. was / will enjoy C. has been / would enjoy D. were / could enjoy
I cannot buy a new computer _____ I save enough money.
A. if B. even if C. unless D. as if
Most people you meet will be polite to you _____.
A. if you are polite to them B. if you will be polite to them
C. unless you are polite to them D. if you were polite to them
If you do so, it _____ the matter worse.
A. makes only B. would only make C. will only make D. had only made
You _____ English fluently unless you practice it every day.
A. will speak B. will not speak C. can speak D. did not speak
Hurry up _____ you will miss the bus and be late for school.
A. if B. and C. or D. as
You will get a good seat if you _____ first.
A. come B. came C. have come D. will come
Sam will not graduate_____.
A. if he passed all the tests B. if he does not pass all the tests.
C. unless he passes all the tests D. unless he had passed all the tests.