“At The Gym” And “In The Gym”? I Found Some … – Languag…
“I work out at the gym.”
This generally refers to a place with exercise and work-out equipment, like a fitness center or a larger membership club, like the YMCA.
“I play basketball in the gym.”
This generally refers to a gymnasium at a school, which consists primarily of a basketball court and bleachers (seats), where school assemblies, pep rallies, gymnastics, gym class, indoor sports, namely basketball, and other activities may take place.
Try not to get too bogged down with prepositions.
You work out AT a location: at the gym.
You play basketball IN a room AT a location: in the gym at school.
You shop AT a location: at the grocery store; at the mall.
However, you also shop AT a place of business, which may be located IN a larger venue:
at the mall in the city; at the shoe store in the mall.