to flatter someone to gain favor
льстить кому-то, чтобы получить одолжение (lstite komu to chtoby poluchit odolzhenie)
"He’s trying to butter up the boss for a promotion."
"Он пытается льстить начальнику, чтобы получить повышение." (on pytayetsya lstite nachalniku chtoby poluchit povyshenie)
to keep changing your mind about something
to appear or arrive dramatically in a situation
to keep one's plans or intentions secret
to act confidently until you actually feel confident
to reassure someone that they can handle a situation
a very clever or talented person