Larusja, I have a question for you. You say, " u nikh ne bilo boleznei". The fact that you put it that way clearly shows it is correct. However I notice that in your version, firstly, the verb to be in the neuter singular does not agree with the subject, and more importantly to me, the subject of the phrase is in the genitive plural. As I said, your version is obviously correct, even though it looks strange to an English speaker; my question is, would it be INCORRECT to say, "u nikh ne bili bolezni" with the verb in the plural agreeing with the subject of the phrase in the nominative case?