blacknomi said:
Hi, I checked my grammar book. Hope it helps. :wink:
1. If the situation is TRUE in present/future
If+ simple present, Subject + simple present or will
--> the situation you assumed may happen.
2. If the situation is UNtrue in present/future
If+ simple past, Subject + would
--> the situation is more imaginary
3. If the situation is UNtrue in past
If+ past perfect, Subject + would have + past participle
--> the situation happened before, but you assumed another different situation.
sabrina
Hi, Sabrina. May I ask which grammar book that came from? Those are pretty good rules of thumb, but they can be a bit misleading.
1. If the situation is TRUE in present/future
If+ simple present, Subject + simple present or will
--> the situation you assumed may happen.
Michael Swan, and probably others, like to use the true/untrue designation, but I prefer real/unreal. A sentence does not have to be true to be placed in these forms. The differentiation is based, not on the truth of the utterance, but on whether the speaker sees the statement as real versus hypothetical, impossible, etc.
[If + simple present, subject + simple present] is a zero conditional. This is used for habitual actions or generally accepted facts.
If one chills water to 32 degrees F, water freezes. (accepted fact)
If one chills water to 32 degress F, water boils.
The second is a false statement, but has the same structure.
If John goes to Pizza Hut, he orders pizza with mushrooms. (habit)
[If + simple present, subject + simple future]
That is a first conditional. It states a condition and then states the speaker's view of the result if the condition is fulfilled.
If one chills water to 32 degrees F, water will freeze.
If I finish work early on Tuesday, I will go to the gym.
2. If the situation is UNtrue in present/future
If+ simple past, Subject + would
--> the situation is more imaginary
This is a second conditional. As you have indicated, it used mostly for unreal (hypothetical, highly speculative, impossible) conditions. The result clause uses [would + base verb] the present conditional.
I just want to add that the verb in the "if" clause is usually in the subjunctive (not simple past), at least in American English.
If I were King, I would free all the prisoners.
The subjunctive mood indicates that the speaker's view of the condition is that it is impossible. (He knows that he is not King.)
When we use the simple past in the "if" statement, we tend to use a non-conditional in the result clause (because it is not strictly a conditional any longer).
If John were there, I would have seen him. (second conditional, subjunctive)
If John was there, I missed him. (not really a conditional)
3. If the situation is UNtrue in past
If+ past perfect, Subject + would have + past participle
--> the situation happened before, but you assumed another different situation.
I would not say that the situation happened before. This structure is used to set up a condition in the past (that didn't happen) and then a result that would have happened had the condition been fulfilled. This is a third conditional. The result clause is in the past conditional.
If I had studied harder in school, I would have made better grades.
This postulates a change in the past that, if fulfilled, would have had a result in the past. If the change in the past results in a change in the present, we use a mixed conditional -- past perfect in the "if" clause and present conditional in the result clause.
If I had studied harder in school, I would be a lawyer today.
My mistake.