to frighten /ˈfraɪtən/ /ˈfraɪtn/
to scare /skɛr/ /skeə/
to intimidate /ɪnˈtɪmɪdeɪt/ /ɪnˈtɪmɪdeɪt/
to startle /ˈstɑːrtl/ /ˈstɑːtl/