The initial idioms of the letter K

knew	know a hawk from a handsaw
know (one's) beans	know chalk from cheese
know every trick in the book	know for a fact
know full well	know (someone) in the biblical sense
know (someone)	know (something) inside and out
know what's o'clock	know which way the wind blows
knick-knack	knickers
knife	knife-edge
knifepoint	knight in shining armor
knight	knit brow
knit brows	knit (one's) eyebrows
knit together	knit up
knit	knitting
knob	knobstick wedding
knock	knock (one's) head against a/the wall