Usage patterns
〈人〉が呆然とするfor someone to be left dumbfounded/dazed
He was left stunned by the sudden news.
呆然と立ち尽くすto stand rooted to the spot in a daze
She stood frozen in shock at the scene of the accident.
呆然とした〈物〉a dazed/blank (expression, look, etc.)
He stood there with a dazed expression on his face.
呆然と〈動詞〉to (do something) in a dazed, absent-minded way
He gazed up at the ceiling in a daze.
