Collocations for stunned - adj.

appear, be, feel, look, seem, sit, sound, stand
Morton stood stunned, unable to believe his ears.

leave sb
Leaving them all stunned, she walked out of the bar.

absolutely, completely, quite, simply, totally, utterly
rather, somewhat
almost
a little, slightly, etc.
for a moment, momentarily, temporarily

at
They seemed stunned at his outburst.

by
She was a little stunned by the news.

with
stunned with grief

Stunned is used with these nouns:
amazement, disbelief, expression, look, silence