i Register
In some senses, painfully is marked as informal. Watch for register when choosing this word.
ADJ.
apparent, clear, cringeworthy, loud, most, obvious, shy, skinny
VERB + PAINFULLY
answer, became, become, glare, impinged, limped, studying, wound
PAINFULLY + NOUN
people, rendition, stairs
PREP.
down, in, on