The reason you become a teacher is to see that one moment where you see the improvement that a student has made.
People often say to me, 'when are you happiest?' I say, 'when I'm teaching in the classroom.'
They work really hard, so I work really hard. I work hard, and they work hard. So we can progress together.
When you see their face after you have taught them something new, and then you see them using that language, it's a very rewarding thing.