know

verb:to be aware of facts, information, or a situation through observation, inquiry, or experience
- She knows all the best restaurants in town.
verb:to be familiar with a person, place, or thing
- I know the neighborhood well because I grew up there.
verb:to possess knowledge or skill in a particular area or activity
- He knows how to fix a broken engine.
verb:to recognize or identify someone or something
- Do you know this melody from the old TV show?
verb:to be sure or certain about something
- I know I locked the door before I left.