Laura Eickoff has an MA TESOL degree from Michigan State University and has taught at universities in Hong Kong, Mainland China, and the United States. She is currently an instructor at a university in Turkey. In this post, Laura explains how to build and modify sentences expressing past unreal conditionals, sometimes known as “the third conditional.”
We use past unreal conditionals to talk about things in the past that were not true (but hypothetically could have been) and the results of what would have happened if that was the case. Simply put: it was possible, but it did not happen.
EXAMPLE 1 If I had known that I was going to be late, I would have called you.
- I did not know that I was going to be late.
- I did not call you.
- The reason I did not call is that I did not know I would be late.
As with other conditionals, we usually use an If clause connected to an independent clause that has a modal in it.
The verb in the if clause is in the past perfect:
If clause (with past perfect) + main clause (with would/could/might + have + past participle)
The If clause (preceded by a comma) could also come after the main clause.
Sometimes, past unreal conditionals are used to express regret. The speakers wish they had done something differently. Example 1 above, in a particular context and spoken with certain intonation, could mean that the speaker regrets not having called. In Example 2 below, the implication of regret is even stronger because the if clause includes only.
EXAMPLE 2 If I had only woken up five minutes earlier, I wouldn’t have missed the train.
You can also use this structure to talk about an imaginary present result. In this case, though, you should use the base form of the verb (not have + past participle) after the modal in the main clause.
EXAMPLE 3 If I had known you were coming to dinner, it would be ready.
- At the point when you arrived, the dinner could have already been ready.
- Too bad you didn’t call ahead.
Example 3 could be expressing regret, depending on the tone or context of the conversation.
The past unreal conditional (the only conditional that uses the past perfect) is sometimes found without the if. All you have to do is move had to a position before the subject and take out the if.
- Had I known that I was going to be late, I would have called you.
- Had I only woken up five minutes earlier, I wouldn’t have missed the train.
- Had I known you were coming to dinner, it would be ready.
These if-less structures mean the same as full-form conditional clauses, but their tone is stiffer and more formal. This structure is not an absolute necessity for students to be able to produce. In fact, it may cause confusion if they try to over-apply this method to other forms of conditionals that don’t use had and function differently. But at least a passive knowledge of this alternative structure might come in handy, should they hear it somewhere.
Had they not learned it from you, they might have wished they had.
Have your students familiarize themselves with these variations of past unreal conditionals with this downloadable activity.
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