Turn polyrhythms into sentences: “I like to drink cherry Coke” works for this one.

I, like, drink, che, Coke - these syllables are the 5 I, to, rry - these syllables are the 3

You’ll notice that I is when both notes happen at the same time.

Now, imagine a measure of 15/8, and the rhythm of the words are spoken like this:

I - dotted quarter note Like to - quarter note, eighth note Drink - dotted quarter note Cherry - eighth note, quarter note Coke - dotted quarter note

Sorry if this sounds confusing and convoluted. I’d make a video to demonstrate, but I’m currently out and about right now lol. I promise it makes sense and works though!