US /kip jʊɚ noz tə ðə ˈgraɪndstoʊn/
・UK /kip jɔ: nəuz tə ðə ˈgraəndstəun/
In English, when you're talking about a job and you say that you need to "keep your nose to the grindstone", it means that you need to keep working hard and not take too many breaks.
It's important when you're a teacher like me, when you're doing this job, that you keep your nose to the grindstone.