"Unless they had sold the house, they wouldn't have so much money"
To zdanie jest w dziale 3rd conditional. Co mnie dziwi to drugi człon zdania, dlaczego nie "wouldn't have had" skoro to 3rd conditional, a nie mieszany?
If they hadn't sold the house, they wouldn't have so much money. --> Gdyby nie sprzedali domu (jakiś czas temu, w przeszłości), to (teraz) nie mieliby tyle pieniędzy. [Dobrze rozumuję?] (ale sprzedali i mają)
If they hadn't sold the house, they wouldn't have had so much money. --> Gdyby nie sprzedali domu, nie mieliby tylu pieniędzy (ale sprzedali i mieli)