When we say the blessing over the chanukah candles or shabbat or yom tov candles, why is the language of "l'hadlik NER" used instead of l'hadlik NEROT? After all, we are saying a blessing over MORE than one candle!

Answer

The answer is that for both Chanukah and Shabbat, it is necessary to light only one candle for the fulfillment of the mitzvah.