knows

Knows is the third-person singular present tense of the verb know. The base verb know denotes awareness of information, certainty about a proposition, or familiarity with a person, place, or thing. Knowledge tends to imply some justification or evidence, while mere belief or guesswork does not.

Grammatical details: Know is irregular; its principal forms are know, knows, knew, known, knowing. Examples: She knows the answer. He knew her from school. They have known each other for years. It regularly takes that-clauses (I know that you are right), questions (Do you know...), and negative forms (I do not know). It can pair with phrases like know-how, know of, and know about, to express familiarity, acquaintance, or awareness of a topic.

Etymology and related terms: The verb comes from Old English cnawan, from Proto-Germanic roots; it has cognates in other Germanic languages, such as German wissen and kennen and Dutch weten and kennen. The noun form knowledge and related adjectives such as knowledgeable derive from the same semantic field. In philosophy, "know" is evaluated in terms of justified true belief; Gettier problems have prompted discussion about the precise conditions under which belief counts as knowledge.