"I would have tried more."
Translation:Θα μπορούσα να είχα προσπαθήσει περισσότερο.
I would have tried more. = Θα είχα προσπαθήσει περισσότερο.
I could have tried more. = Θα μπορούσα να είχα προσπαθήσει περισσότερο.
This sentence is a zombie (or ghost) one. Which means that, even though it's either been deleted or fixed, it still lurks around. Mostly on Stregthening exercises. We have reported this issue and there might be a solution to it, but we'll have to find every single one of them, then wait and check. :)
I've just finished the test out of this section and I'm afraid there are still lots of them. LOTS. Unfortunately, many don't even have the "Report a problem -> The Correct solution is unnatural or has an error. / My answer should be accepted." options available, so there's not much we can do on our end to help you spot them.
Not meant to be, the sentences were done at random with the words assigned to the unit. Sorry, it came last nothing was being implied. :-)) I think you are a very strong learner and have really tried. And I hope have succeeded as you wished.