to declare to be untrue; to deny
否 (fǒu) · 7 strokes
Originally the same character as 不. Distinguishing component 口 was added later to the character when it took on the meaning "not". 不 represents the sound.
认 (rèn) · 4 strokes
Phonosemantic compound. 讠 represents the meaning and 人 represents the sound.