Now all we have to do is keep it burning well.
You must stay here, keep the fire burning well.
That meant it would burn well when the rain finally stopped and the house's shelter was no longer needed.
Expensive, but they drew little current, and might well burn for centuries.
Cooking oil can burn well and may catch fire if it is used at too high a temperature.
Later in the year it would burn well, but not now.
Everyone knows that a fire needs oxygen to burn well.
That did not even burn well, as Samuels used to say.
The book caught fire eventually but did not burn well.
But what if your fire is not burning well or, worse, has gone out?