Translation:The house of the Kovács family is big, and its door is open.
You will know next time. :) But please report these cases, they were accidentally left in the course, they need to be corrected.
Also, "ajtója" may be correct, but "ajtaja" is the more common version.
They should have used Smith in both languages. Smithék háza nagy = Smiths' house is big.
Perhaps, but isn't Kovacs the same widespread family name as Smith in English?
Kovacs is also the literal translation of Smith, since both come from the word (black)smith. And as Smith it became a very common surname because there were a lot of blacksmiths.