ESL

So my son got his first job at age 17. He went to his first day of work today and the person training him was from a foreign country and told my son that if he messed up some of his English throughout the night, that my son should correct him.

A lady came in to the establishment and asked "do the smoothies have any dairy in them?". The "trainer" promptly answered "No, no dairy in the smoothies". The lady then purchased a smoothie and left.

After the lady had gone, the "trainer" asked my son, "what does dairy mean?".