Repeat the verb in yes/no questions. Often yes/no questions are straightforward and to the point -- as a result, we answer "yes" or "no." Seems pretty logical, right? Nope. That's not how it works in the land of Saints and Scholars. When asked, repeat the noun and verb.
For example, "Are you going to Jane's party tonight?" --"I am."
"Does Ireland have unicorns?" --"It doesn't.