Writing Balance Rule: The left side (月) is narrower and elongated, while the right side (思) is wider, composed of a field over a heart, requiring careful horizontal spacing so the character does not look lopsided.
1. Meaning
cheek (the side of the face below the eye)
gill (of a fish)side or part resembling a cheek
NounNeutral#anatomy#body parts#biology
Sample Usage
他害羞得两腮通红。
tā hàixiū de liǎng sāi tōnghóng.
He was so shy that both his cheeks turned red.
金鱼的腮在水里一张一合。
jīnyú de sāi zài shuǐ lǐ yì zhāng yì hé.
The goldfish's gills open and close in the water.
2. Sound
/[saɪ̯˥˥]/Tone: 55
腮
sāisai1
|
++
¯(55)
=sāi
Build the syllable
Step-by-step blending
sai
Tone mark placement: Tone mark sits on "a" per main-vowel priority (a > e > o; in -iu/-ui the mark takes the second vowel).
Tongue & Mouth Position: Tip of the tongue is brought close to the back of the upper teeth or alveolar ridge, allowing air to friction gently.
Final Rhyme
ai
Vowel Group: -a vowel group
Sounds like: -ai rhymes with 'eye'
Mouth Shape Guide: Pronounce as standalone vowel 'eye'.
Common Learner Trap: Keep vowel quality steady across all 4 tone contours.
Tone
T1 (55)
5 → 5 (55)
1st Tone (High-Flat)
Tone Pitch & Cadence: Tone 1 is a steady, high register pitch, comparable to the flat pitch of a musical note held high or a monotonous 'bee' sound.
👂
Listening trap: Confusing the high level tone (Tone 1, sāi) with the rising tone (Tone 2, sái) or falling tone (Tone 4, sài), which alters meaning entirely.
👋
Physical Tone Gesture: Hold a flat, high horizontal hand gesture in front of your upper chest to match the steady, high level pitch of Tone 1.
3. Writing
Topology: Left-right · Strokes: 13 strokes
Writing Balance Rule: The left side (月) is narrower and elongated, while the right side (思) is wider, composed of a field over a heart, requiring careful horizontal spacing so the character does not look lopsided.
4. Components
Radical月 · Flesh / Moon Radical (flesh, body parts (when appearing on the left side as a variant of 肉))
Semantic Clue (形旁):月 (Indicates body parts or flesh (flesh of the face))
Phonetic Clue (声旁):思 (original sound: sī / sāi)
Flesh (月) combined with thought/mind (思) creates the soft flesh of the face where emotions and thoughts show: the cheeks.
月 flesh / body part semantic indicator
思 phonetic and conceptual hint
Phonetic Family (形声字家族)
7· Phonetic Root: 思 (sī)
5. History
Liushu category: Phono-semantic (形声)
Origin: Combined from 月 (flesh) to denote a body part and 思 (sound/meaning hint), formalized in later dynasties to specify the cheeks of the face.
Semantic Evolution: Originally referred specifically to the flesh of the cheek, later extended to fish gills (鱼腮) due to structural similarity.
The character bridges physical human anatomy and anatomical terms used in zoology.
6. Sinosphere
🇻🇳
Sino-Vietnamese
tai
The Sino-Vietnamese reading 'tai' corresponds to the historical sound layer, though modern Mandarin uses 'sāi'.
🇯🇵
Kanji (Japanese)
On: サイ (sai) / Kun: あご (ago)
🇰🇷
Hanja (Korean)
腮
7. Memory
Vivid Mnemonic Story
Imagine pressing your flesh (月) against your hand while deep in thought (思), resting your head right on your cheek.