Cách sử dụng
"Keep your hand in" means to keep practicing or maintaining a skill so that you don't forget how to do it. It's like keeping your hand or body engaged in a certain activity, so that you can stay familiar with it. It's often used when someone has been away from a particular activity or skill for a while, and needs to work to make sure they still remember it. For example, if you used to play the guitar but haven't picked it up in a while, someone might suggest that you "keep your hand in" by playing some simple chords each day to make sure you don't forget how to play.