adverb
Describes a sudden, brisk movement or action. Often used with verbs of motion or change.
彼はつと立ち上がった。
He quickly stood up.
adverb
Implies a composed, unhurried manner. Less common than the 'quickly' sense.
彼女はつと微笑んだ。
She smiled calmly.
adverb
Used for looking or focusing with concentration. Often collocates with verbs like 見る or 見つめる.
彼はつと私の顔を見つめた。
He stared intently at my face.