Radical studio
口 Mouth
A small square that shows talking, eating, and many question or particle words.
Meaning and position
Meaning: mouth, opening
Where it sits: Often left or bottom; also the whole character 口.
Speech lives here
口 is the square you already write in 吗, 吃, and 叫. It is not decoration — it flags mouth-related meaning.
Particles that sit at the end of a question often include 口 because they are spoken tags, not content nouns.
When two characters share 口, compare the rest of the shape instead of restudying the square.
Eating and calling
吃 “eat” and 喝 “drink” both involve the mouth. 叫 “to be called / to call” is speech.
Keep 口 small. Beginners often draw it too large and crowd the other strokes.
Say the example words aloud while you look at 口 so sound and shape lock together.
Example characters
yes-no question particle
口 plus 马 — a spoken tag, usually neutral tone.
eat
Mouth radical with a right side you will reuse in food talk.
be called / call
Use in 我叫… introductions.
Takeaways
- 口 is a square, not a circle.
- Expect it in talking, eating, and some particles.
- Write it compact so the rest of the character can breathe.