In English, there are four kinds of conditional sentences:
TYPE ZERO CONDITIONAL: If (present tense) + present tense
“Type Zero” conditionals are used when you are thinking about something that is always true as a general rule, for example:
If people don’t use seat belts, they easily get hurt in accidents.
I always get a rash if I eat eggs.
TYPE ONE CONDITIONAL: If (present tense) + modal follwed by base form of the verb
“Type One” conditionals are used when you are thinking about something that is possible or likely in the future, for example:
If I do well in this class, I am going to take English 1A next
If you fail the first test, you may find the rest of the course very difficult.
If your cell phone goes off, you should turn it off without answering it.
If I can’t come to class, my friend will get me the homework assignment.
Note: present perfect counts as present in conditional statements:
If I have made any mistakes, I will correct them.
TYPE TWO CONDITIONAL: If (past subjunctive) + modal followed by the base form of verb.
“Type Two” conditionals are used when you are imagining something that is impossible or unlikely, for example:
If I had more money, I would get a new car.
If the boss knew how busy you are, he might not ask you to do any more.
If I had wings, I could fly.
If wishes were horses, beggars would ride. (old proverb)
Note: The subjunctive is in the process of disappearing from the English language. In Shakespeare and in the King James Bible, for example, you can find many examples of the subjunctive that we no longer use (“Blessed be the meek,” “Would that he were here,” etc.).
In modern English, the most common use of the subjunctive is is type two conditional statements. The past subjunctive and the simple past tense are the same EXCEPT for the verb to be:
Simple past: I was, he/she/it was, you were, we were,
Past subjunctive: I were, he/she/it were, you were, we
were, they were
Some people no longer use the past subjunctive “were” in conditional statements, saying things like “if I was you” instead of “if I were you.” Your instructor is of the old school and likes the subjunctive.
TYPE THREE CONDITIONAL: If (past perfect) + modal followed by “have,” followed by the past participle.
“Type Three” conditionals are used when you are imagining something that did not happen in the past:
If he had called me, I could have given him directions.
Note how a negative is formed in the main clause:
If she had known about his drinking problem, she would not have married him.
If he had been wearing his seat belt, he might not have been hurt.
Exercise: Finish the following sentences:
1. If I won a million dollars in the state lottery,
2. If I have time this weekend,
3. If I had stayed in my country,
4. If my English writing skills were better,
5. When my English writing skills get better,
6. If my English had been better,
7. If he had seen the traffic light,
8. If real estate in the Bay Area weren’t so expensive,
9. If I were in Hillary Clinton’s position,
10. If she didn’t have to work full time,