Answer:
Do not understand what the sign says.
Step-by-step explanation:
In this example, the hotel clerk informs Ernesto and his mother the importance of flushing the toilet. He describes what the two of them should do and then states: "that's what the sign says." The fact that the hotel clerk feels the need to state what the sign says indicates that he most likely believes them to be incapable of understanding what the sign says.