The above sentence is a translation exercise in Wheelock's Latin, and the official answer isYou do recognize how great the danger is, do you not?
"Nonne recognovisti quantum esse periculum?"
Yet I think that since this English sentence contains an indirect question, rather than an definite statement, it should be translated with a subordinate clause with its verb in subjunctive, which yields "Nonne recognovisti quantum sit periculum?"
Are these two versions equally acceptable or have I missed something?