Identify the part of the sentence which is not grammatically correct.
Remember to switch off your mobile phone at the movie hall.

Correct option is D

· Error Identification: The error lies in option (d) "at the movie hall". The correct phrase should be "in the movie hall" instead of "at the movie hall".
Detailed Explanation:
· Why "at the movie hall" is incorrect: The phrase "at the movie hall" suggests a general location, but it doesn’t clearly convey being inside the movie hall. Since the instruction is specifically about switching off a mobile phone, the context implies that the person is already inside the hall. Therefore, "in the movie hall" is a more precise and contextually accurate choice.
· Correct Usage: When referring to being inside a location, like a movie hall, "in" is the more appropriate preposition. This suggests that the action (switching off the phone) should happen within the enclosed space of the movie hall. In English, "in" is generally used for locations that have a physical boundary or enclosure, which applies here.
Corrected Sentence:
"Remember to switch off your mobile phone in the movie hall."
Grammatical Rule:
· The preposition "in" is typically used to indicate a position within an enclosed area or space, such as rooms, buildings, and vehicles. For example:
· "He is in the classroom."
· "She’s in the car."
· "They are in the mall."
· Conversely, "at" is used to refer to a general location or point, not necessarily within an enclosure. For example:
· "I’ll meet you at the station."
· "He’s at the entrance."
In this sentence, since we are referring to being inside the movie hall when switching off the mobile phone, "in the movie hall" is correct.
Example for Clarity:
· Incorrect: "Please remain quiet at the library."
· Correct: "Please remain quiet in the library."
Using "in" clearly indicates the action should take place within the boundaries of the library, just as "in the movie hall" specifies the enclosed space where the phone should be switched off.