The sentence - “She smiled(v) friendly(adj)” is wrong
since adjective can’t modify a verb.
Can I say “She smiled(v) friendlily(adv).” instead of
“She smiled in a friendly way”.
Hi,
I am afraid ‘friendlily’ is not used much simply because it is difficult to enunciate although it does technically exist. I would suggest: Gave (me) a friendly smile/smiled (at me) in a friendly way/manner.
Alan