I not heard the word «pupil» from when I went to the high school. In 1976 here we began the high school at 13 years old. I had a different teacher of English each year during five years. This are beautifull memories. I always wished learn English.
I searched the lyrics of the song in www. The pronouncing of the singer is very clear.

It's a very ancient saying
But a true and honest thought,
That if you become a teacher,
By your pupils you'll be taught.

As a teacher, I've been learning
You'll forgive me if I boast.
And I've now become an expert
On the subject I like most,

Getting to know you.

aHHHH

Getting to know you, getting to know all about you
Getting to like you, getting to hope you like me
Getting to know you,
Putting it my way, but nicely
You are precisely my cup of tea!

Getting to know you, getting to feel free and easy
When I am with you, getting to know what to say.
Haven't you noticed?
Suddenly I'm bright and breezy
Because of all the beautiful and new things
I'm learning about you day by day.

Repeat Refrain