He was attracted by her smile.
- Il était attiré par son sourire.
Her smile expressed her thanks.
- Son sourire exprimait sa gratitude.
That person has had an odd grin on his face for a while. What do you suppose is behind it?
- Cette personne a eu un étrange sourire sur la figure pendant un instant. Que pensez-vous que cela cache ?
He grinned broadly at us.
- Il nous fit un large sourire.
I saw a joyful smile on his face.
- Sur son visage, je vis un joyeux sourire.
She always talks with a smile on her lips.
- Elle parle toujours le sourire aux lèvres.