straighten up
Anfänger (A2) informal
To sit or stand up straight, to make a room look tidy, or to start behaving better.
"Straighten up when you sit at the computer — slouching is bad for your back."
To sit or stand up straight, to make a room look tidy, or to start behaving better.
"Straighten up when you sit at the computer — slouching is bad for your back."