Plug away and Stick to

Plug away verb - Work doggedly or persistently.

Stick to and plug away are semantically related in work hard at topic. In some cases you can use "Stick to" instead a verb "Plug away".

Stick to verb - Stick to firmly.

Plug away and stick to are semantically related in work hard at topic. Sometimes you can use "Plug away" instead a verb "Stick to".