One of the sentences to be translated in level 4 session 4 is as follows: We could buy a bigger house with a pool and a garden next to the beach. The answer indicates that the verb should be in il passato prossimo, Abbiamo potuto comprare una casa più grande con una piscina e un giardino accanto alla spiaggia. It seems to me that the verb potere needs to be in il condizionale or potremmo, rather than in the past since there is the implication of an "if" clause even though there is none present, e.g. We could buy the house if some condition were met. I realize that the conditional has yet to be introduced, but I also know that throughout the course to this point we have had several things to "unlearn" and I wonder if this is another one?