My sore

Hi Natsuko,

If you say, "I can't get rid of my sore," it means you have a  visible wound (like a cut or scrape in your skin that you can see).  

If you don't mean to say that and you want to say that your body is still hurting from the exercise, you would say something like "I went to the gym last week.  Although a week has passed since I went to the gym, I am still feeling sore. or "my body is still feeling sore and I can't get rid of the feeling. "

You might also say "I can't get rid of the pain from exercising."