The 3rd Conditional is NOT difficult, so stop thinking it is! hehe. It just takes time to understand the structure and then implement it!
The structure is like this:
If + past perfect (had +past participle ) + Would + present perfect (have + past participle)
example: If I had known about the party, I would have gone.
Here is a GREAT excerpt from the movie Benjamin Button where you can see it in context.
And I have taken the time to transcribe the dialogue so that you can read along with the movie.
Sometimes we are on a collision course and we just don’t know it.
Whether it is by accident, or by design, there is not a thing we can do about it
A woman in Paris was on her way to go shopping, but she had forgotten her coat, went back to get it. When she had gotten her coat, the phone had rung, so she had stopped to answer it and talked for a couple of minutes. While the woman was on the phone Daisy was rehearsing for a performance at the Paris opera house. While Daisy was rehearsing, the woman had gone outside to get a taxi.
Now the taxi driver had dropped off a fare earlier and had stopped to get a cup of coffee, and all the while Daisy was rehearsing, and this cab driver who had dropped off the earlier fare, had stopped to get the cup of coffee, who picked up the lady who was going shopping, and had missed the earlier cab. The taxi had to stop for a man crossing the street who had left for work 5 minutes later than he normally did, because he forgot to set his alarm. While that man, late for work, was crossing the street, Daisy had finished rehearsal, and was taking a shower, and while Daisy was showering, the taxi was waiting outside a boutique for the woman to pick up a package, which hadn’t been wrapped yet, because the girl that was supposed to have wrapped it had broken up with her boyfriend the night before, and forgot. The package was wrapped, the woman was back in the cab, which was blocked by a delivery truck, all the while, Daisy was getting dressed. The delivery truck pulled away and the taxi was able to move, while Daisy, last to be dressed, waited for one of her friends who had broken a shoe lace, while the taxi was stopped waiting for a traffic light, Daisy and a friend came out of the back of the theater, and if only one thing had happened differently, if that shoe lace hadn’t broken, or that delivery truck had moved moments earlier, or that package had been wrapped ready because that girl hadn’t broken up with her boyfriend, or that man had set his alarm and gotten up 5 minutes earlier, or that taxi driver hadn’t stopped for a cup of coffee, or that woman would have remembered her coat, and got into an earlier cab, Daisy and her friend would have crossed the street and the taxi would have driven by.
Print the transcription and then underline all of the past and present perfect tenses and then write 5-10 sentences of what would have, or wouldn’t have happened, if only 1 thing had been different.