一问三不知

lit. to reply "don't know" whatever the question (idiom) / fig. absolutely no idea of what's going on / complete ignorance

one / single / a (article) / as soon as / entire; whole; all; throughout / "one" radical in Chinese characters (Kangxi radical 1) / also pr. [yao1] for greater clarity when spelling out numbers digit by digit

to ask / to inquire

to ask; to inquire

three / 3

the three no's (abbreviated catchphrase)

no; not so / (bound form) not; un-

to know nothing about the beginning, the middle or the end / to know nothing at all

not to know / unaware / unknowingly / fig. not to admit (defeat, hardships, tiredness etc)

to know / to be aware