Okay kiddo, so a clinical pharmaceutical scientist is someone who helps make sure that the medicine people take is safe and works the way it's supposed to.
Imagine you have a toy that is supposed to light up when you press a button. A clinical pharmaceutical scientist would be like the person who checks to make sure that the toy lights up every time you press the button, and that it won't hurt you if you accidentally swallow it.
But instead of toys, clinical pharmaceutical scientists work with real medicines that can help people feel better when they're sick. They test the medicine in experiments to see how well it works, how safe it is, and if it could cause any problems for people who take it.
They also work with doctors and other scientists to figure out how much medicine people should take, how often they should take it, and if there are any special instructions they need to follow.
So basically, clinical pharmaceutical scientists are like superheroes who make sure the medicine we take can help us, and not hurt us. Pretty cool, huh?