The character 口 (kǒu): mouth

On a cream ground, at the left, a round cartoon face in coral pink: two round dark teal eyes, a small rounded nose, blushing cheeks, and a wide open mouth, deep pink inside, with a cream tongue at the bottom. At the right, at the same height, the character 口 in very dark brown: a plain upright rectangle drawn as a thick empty frame, taller than it is wide, its sides very slightly closer together at the foot.

Pronunciation: kǒu
Strokes: 3
Level: HSK 3
Radical: 口

What it means

mouth; classifier for things with mouths (people, domestic animals, cannons, wells etc); classifier for bites or mouthfuls

Where its shape comes from

An open mouth seen from the front. Xu Shen defines it by what it does, "that by which a person speaks and eats", and files it among the figurings. On the oldest inscriptions the outline is rounded, close to an oval; the rectangle we write today is a regularisation, as with every circle in Chinese writing, which a brush does not draw.

Source: Xu Shen, Shuowen Jiezi (121 CE); the Chinese University of Hong Kong character database.

A way to remember it

Three strokes make the rectangle, and it is slightly narrower at the bottom than at the top. Leave the inside empty: the moment you put a bar in there you no longer have the mouth, you have the sun.

This is a memory aid, not the origin of the character.

Words it appears in

入口 rù kǒu · HSK 4 entrance; to import
出口 chū kǒu · HSK 5 an exit; CL:個|个[ge4]; to speak; to export; (of a ship) to leave port
进口 jìn kǒu · HSK 5 to import; imported; entrance; inlet (for the intake of air, water etc)
人口 rén kǒu · HSK 5 population; people
口味 kǒu wèi · HSK 5 a person's preferences; tastes (in food); flavor
借口 jiè kǒu · HSK 5 to use as an excuse; excuse; pretext

Writing it

See the stroke order of 口, animated stroke by stroke.