Student or Learner
Could anyone tell me what's the difference between "Keep" and "Keep on". For example, "He keeps talking" and "He keeps on talking". They sound the same to me.
But it may differ to what you want to stress.
He keeps talking: Here you just stress the action, namely the talking.
He keeps on talking: Here you also stress the "talking" but in this case it sounds more that you want to stress that it is annoyance.
eg: Although she told him to shut up, he kept on talking.