Prone to silly examples

(Daddy reads passage in novel in which the Doctor "lies prostrate")
E (lying on back): "Is prostrate like this?" (rolls onto front) "Or this?"

Me: "Prostrate is lying on your front. Good job, knowing it's one of those! It's also called 'prone', which you can remember because they start with the same letters".

E (rolls onto back again): "What's the word for this again?"

Me (putting book aside): "That's 'supine'. You can remember because normally (lies on front on floor) those little quilly mammals are porcuprone. If they're porcusupine they need your help."

E: "Is there a special word for lying on your side?"

Me: "Probably! I can't think of any though. At some point you need to leave those poor porcupines alone. Also, it's definitely no good if after a storm, you go outside and the woods are full of supine trees".