to behave as if something is true when you know that it is not, especially in order to deceive people or as a game
PRETEND
to say that you're wrong about something
ADMIT
to not tell anyone something that you know
KEEP (SOMETHING) A SECRET
to invent something, such as an excuse or a story, often in order to deceive
MAKE UP
to tell someone that you will certainly do something
PROMISE
