Take the adjective, coy, for a person who pretends to be shy but really isn't, or someone who could give a definite answer but won't. Coy behavior can be playful or just plain annoying.

Pronunciation: / kɔɪ/
English description: affectedly modest or shy especially in a playful or provocative way
Synonyms: overmodest
Chinese Translation: 做作的(zuo4 zuo de)
Spanish Translation: tímido
ORIGIN: Originally meaning "quiet and shy," today someone who is coy pretends to be shy in a playful manner — often as a form of flirting. If a politician is coy about something, he or she only gives vague statements on an issue for fear of committing to a position or angering his or her constituency. Common to both of these senses is the fact that a person uses coyness to subtly manipulate his or her audience.

EXAMPLE SENTENCE:

Politics remains a mostly background presence in the tweets collected in the book, typically only raised as a subject of coy allusion.
He cannot receive money from tournaments, equipment manufacturers or agents and was coy as to whether his club maker would try to market his irons.

*New word description, story and part of "EXAMPLE SENTENCE" are cited in Vocabulary