Why does he put “a” before “Yes”? Is “yes” a countable noun?
Native speaker’s answer
Rebecca
Yes. Hiccup puts "a" before "yes" because he is, in fact, counting the yeses in response to his daughter's questions. Usually, "yes" is not a countable noun. In this situation, however, Hiccup is being asked a ton of questions by his daughter and the majority of his responses have been "yes."