to touch someone lightly with your fingers, making them slightly uncomfortable and often making them laugh (v)
tickle /ˈtɪk.əl/ --> I tickled her feet and she laughed.
to make someone realize a possible danger or problem (v) (cảnh báo)
warn /wɔːrn/ --> Put that ball down now, Laura - I'm warning you
generous, helpful, and thinking about other people's feelings (adj)
kind /kaɪnd/ --> He's a very kind and thoughtful person.