One phrase, 2 meanings. Learn them one at a time, then test yourself.
Meaning 1 · most common
to give something you have to another person, especially after you have finished using it or when you no longer need it.
Example
A: I got this book from Sarah. Do you want it next?
B: Sure, just pass it on to me when you’re done.
Tell it apart
I passed my notes on to her.
My grandfather passed away.
Meaning 2
To pass something on to someone means to send information, a complaint, or another matter to the person who should deal with it.
Example
A: What happens to my complaint now?
B: I'll pass it on to the duty manager.
Tell it apart
Read the sentence, then pick the meaning that's in play.
Pick a meaning and say it out loud. Save the ones you mix up.