to keep at it (to continue/persevere with something difficult)
A: I’m thinking about quitting college. I can’t manage all the work.
B: I know it is hard, but you have to keep at it. It will get easier.
A: How did you become so good at speaking English?
B: I just kept at it. Even when it became really difficult and I couldn’t understand my teacher, I just kept at it.
Can you make a sentence using to keep at it?