know (EN)
verb, noun

verb “know”

know; he knows; past knew, part. known; ger. knowing
  1. to be sure about something
    I know for certain that the keys are in the drawer because I placed them there myself.
  2. to be aware of
    Did you know that they are divorced?
  3. to be familiar with someone or something through personal experience
    I know the owner of that shop; we went to school together.
  4. to comprehend something as a result of learning or experience
    After years of research, she knows the subject inside out.
  5. to have gone through certain situations or events
    He has known hardship and isn't afraid of hard work.
  6. to have the skill or ability to perform a musical piece
    Do you know Moonlight Sonata?

noun “know”

know, singular only
  1. the condition of being informed or having information (used mainly in the phrase "in the know")
    Only a few people are in the know about the surprise party we're planning.