beatutiful heart“
- I keep on studying english.
- I keep studying engilsh.
”
According to Longman
keep (on) doing something
I keep thinking about Joe, all alone in that place.
I keep telling you, but you won't listen!
She pretended not to hear, and kept on walking.
Keep/ Keep on ( to continue doing something )
They are the same, other examples:
Should I keep studing chinese ?
Why do I keep on studying economics ?