know (something) backwards

know (something) backwards

To be extremely familiar with a particular subject, field, or piece of writing, film, music, etc. Primarily heard in UK. I've read this book so many times, I know it backwards. You should ask Samantha about your car. She knows engines backwards.
See also: backward, know
Farlex Dictionary of Idioms.

know something backwards

mainly BRITISH or

know something backwards and forwards

mainly AMERICAN
If you know a subject backwards, you know a lot about it. I thoroughly enjoy lecturing and know my subject backwards. He will be very much in demand. He knows the business backwards. They know company personnel policy backwards and forwards.
See also: backward, know, something
Collins COBUILD Idioms Dictionary, 3rd ed.

know something backwards

be entirely familiar with something.
1991 William Trevor Reading Turgenev People who lived in the town knew it backwards.
See also: backward, know, something
Farlex Partner Idioms Dictionary

know somebody/something ˈbackwards

(informal, especially British English) know somebody/something extremely well: He must know the play backwards by now — he’s seen it six times!
See also: backward, know, somebody, something
Farlex Partner Idioms Dictionary
See also:
  • (one's) true colours
  • (Someone or something) called, they want their (something) back!
  • tomorrow
  • banner
  • one rotten apple spoils the (whole) barrel
  • one rotten apple spoils the (whole) bushel
  • rotten apple spoils the barrel
  • a bad apple spoils the (whole) barrel
  • a rotten apple spoils the (whole) barrel
  • a rotten apple spoils the (whole) bunch