'As' is correct.
Rover

English Teacher
Which one is correct AS or IN?
Context:
She bent her head as/ in a sign of gratitude.
'As' is correct.
Rover
I think "in" is possible.
I could go either way.
@ Mad-ox:
If you're struggling to get your head round this subtle difference, so am I.
I'd never think of saying 'in a sign of gratitude'.
Rover