How can I explain to my kid that it is normal to lose teeth?

So I’m wondering experience and ideas on how to go about losing teeth with my 5 year old. He is limited in his speech (about as far as my 2 year old) and has pretty noticeable delays when it comes to expressing what is going on with him especially if it’s new. How will I be able to tell he is loosing one and how do I explain what is going on to him that he will understand? I know they can loose thier teeth at anytime now so I just want to be prepared for when that comes.