If he could breathe without mechanical aid, so much the better.

In a few minutes, the patient seemed to be breathing without effort.

It is air, so I can breathe without the helmet.

He would not be able to breathe without a machine.

And he was able to breathe human air without much difficulty.

In a few more seconds it was possible to breathe without danger.

The others breathed without a sound and didn't dare move.

If enough of the lung is involved, it may not be possible for a person to breathe without support.

It hurt, yet he seemed able to breathe without difficulty.

And we couldn't breathe without the machine we're standing in.