Portuguese
The Portuguese language is the only major Romance language to use echo answers often, even if it has words for "yes" and "no" proper (sim and não respectively.). Portuguese will most commonly answer a polar question in the affirmative by repeating the main verb.
For example, one would answer the question, "Tens fome?" ("Are you hungry?" or transliterated as "Do you have hunger?") by simply replying, "tenho" (" have"). One could also add sim before or after the verb for the use of emphasis, or to contradict a negative question; producing "sim, tenho" or "tenho sim". In order to produce a negative answer to a polar question, the verb is repeated followed by não before or after it. Thus, a negative answer to our above question would be: "Não tenho," "Tenho não," or "Não tenho fome." For emphasis, one could even say, "Não tenho, não."
Read more about this topic: Echo Answer