It’s very easy to tell when someone on TV is learning on the job. It’s often very painful to watch.
What do I mean by “learning on the job”? It’s quite simple. There are two basic scenarios at play: In one, a child or young adult actor is cutting their teeth on camera. In the other, a former athlete is transitioning to become an analyst (for their respective sport). I will take note of some improvements in either case, though it is still difficult to watch in the meantime.
Acting Is for Beginners
Once in a blue moon, you will come across a wonderful child actor who appears to have his/her priorities in order. This kid is very professional and you will hear wonderful things about him/her by older co-stars, especially well-known veterans in the entertainment industry. (Mara Wilson, Dakota Fanning, and Abigail Breslin quickly come to mind. So does Jonathan Jackson, who started acting when he was about 11 years old.)
Most other kids are naturally rough out of the gate. This is part of the reason why young adults are hired to play teenagers. Chances are, those older actors have been working hard at their craft for at least five years; it shows in the way they are able to deliver their lines and successfully convey emotion.