Answer:
1 If I don't pass the exam, I will do it again in January will +(do) = future
2 You'd sleep better if you drank less
coffee. ( drank= irregular simple past)
3 Don't buy it unless you are sure you
like it. (are= irregular simple present agrees with we and you)
4 If I could change a part of my body, I would change my nose. (would + change = conditional)
5 As soon as he arrives, we can have
dinner. (arrive + s = simple present tense that agrees with third-person singular subject)
Explanation: The form of the verb helps to express the time and conditions when the action takes place.
Many are irregular, and you just have to memorize them and practice using them.
