He'd better shape up soon, or he'll fail the class.
If you tell someone to shape up, you are telling them to start behaving in a sensible and responsible way. It is no use simply to tell adolescents to shape up and do something useful
If you ask how someone or something is shaping up, you want to know how well they are doing in a particular situation or activity. I did have a few worries about how Hugh and I would shape up as parents Girls are being recruited now. I heard they are shaping up very well
If something is shaping up, it is starting to develop or seems likely to happen. There are also indications that a major tank battle may be shaping up for tonight The accident is already shaping up as a significant environmental disaster It's shaping up to be a terrible winter