frighten · frightened · frightening · frightens
怖がらせる
the savagery of his thoughts frightened him
彼の考えの残忍さが彼を怖がらせた
怖がらせてやめさせる
if you say anything to him you might frighten him off
彼に何か言うと彼を怖がらせてやめさせるかもしれない
怖がる
at his age, I guess he doesn't frighten any more
彼の年齢なら、もう怖がらないと思う