在体操馆里用英语可以说"at the gym"或"in the gym".
"Gym"是英文"gymnasium"的缩写，"gymnasium"来源于希腊语"gymnasion"，意思是"健身场所"或"体育场馆".
下面是一些使用"at the gym"或"in the gym"的例句及其中文翻译:
"I'm going to the gym to work out." (我要去体操馆锻炼身体。)
"I usually spend an hour at the gym every day." (我通常每天在体操馆呆一小时。)
"There are a lot of people at the gym today." (今天体操馆里有很多人。)
"I'm meeting my friend at the gym later." (我稍后会在体操馆和我的朋友见面。)