ADV

fast, quickly, rapidly
slowly
deeply
shallowly
hard, heavily
They were both breathing hard from the steep climb
gently
easily, steadily
She was beginning to breathe more easily
normally, properly
I can't breathe properly? I'm gasping for air!
raggedly
He was breathing raggedly, mouth open
in, out
She breathed slowly in and out

VERB + BREATHE

can/can't, could/couldn't, could barely/hardly/scarcely
not dare
He hardly dared breathe in case they heard him

PREP

through
Always breathe through your nose

ADV

huskily, softly
'I love you,' she breathed softly