I'm going to the gym.这句话有语法错误吗?

I'm going to the gym ________ A.yesterday B.tomorrow C.last Sunday 选哪一个? I'm going to the gym.这句话有语法错误吗? I am going to the gym这句话有语法错误吗 I want to the gym this morning. They are going to the gym.（改为否定句） i do not fee comfortable going to the gym to work out.怎么翻译work out才合适? i'm starting to lose wight since i started going to the gym.第个start为什么跟to do形式?第2个start为什么又是跟doing 的形式?搞不懂呀 i went to the gym this morning (对画线部分提问) went to the gym 提问 I'm going to the Great Wall. i'm going to do the high i went to the gym yesterday.划线部分the gym对划线提问 I'm going to hit the sack,I'm exhausted.( I'm going to go to the park.还是I'm going to the park.一般将来时be going to I’m at the gym working out. 不懂working out I'm going to the a_____.I'm going to take the plane. I'm going to I'm going to I'm going to