Keep on and Work at

Keep on verb - Allow to remain in a place or position or maintain a property or feature.

Work at and keep on are semantically related in persist topic. In some cases you can use "Work at" instead a verb "Keep on".

Work at verb - To exert effort in order to do, make, or perform something.

Keep on and work at are semantically related in persist topic. Sometimes you can use "Keep on" instead a verb "Work at".