Reduplication of Adjectives (红红的, 高高兴兴的)
Doubling an adjective makes it more vivid and lively. One-syllable adjectives go AA + 的 (红红的 “nice and red”). Two-syllable ones go AABB + 的 (高高兴兴的 “happy”) — each character doubles, the mirror of the verb pattern (ABAB). As an adverb it ends in 地 (认认真真地写).
Why this trips learners up
One of the most charming features of Chinese is reduplication — doubling a word to make it more vivid. With adjectives, repeating them adds a soft, lively, descriptive colour (not “more” in degree, but more painterly). For a one-syllable adjective, just double it and add 的: AA + 的 — 你的脸红红的 (“your face is all red”), 小狗的耳朵长长的 (“the puppy’s ears are nice and long”).
For a two-syllable adjective, you double each character — AABB: 高兴 → 高高兴兴, 干净 → 干干净净, 漂亮 → 漂漂亮亮. This is the exact mirror of verb reduplication: two-syllable verbs repeat the whole word (ABAB: 研究研究), but two-syllable adjectives repeat each character (AABB). Mixing them up — 干净干净 for the adjective — is the classic slip.
The ending depends on what it modifies. Before a noun, use 的: 干干净净的房间 (“a spotless room”). Used as an adverb before a verb, use 地: 他认认真真地写作业 (“he does his homework diligently”). Same “de” sound, different character — 的 for nouns, 地 for verbs.
Two cautions. Not every adjective reduplicates — it’s mostly the vivid, physical-descriptive ones (colours, sizes, shapes, moods). 好吃, 便宜, 麻烦 don’t take AABB (好好吃吃 ✗); when in doubt, just use 很 + adjective. And when an adjective acts as a predicate (verb-like, with no noun after), it switches to the verb’s ABAB pattern and drops 的: 周末该放松放松了 (“time to unwind this weekend”) — roughly the same as 放松一下.
The structure
Colour key
Each colour marks one grammatical role — and the same colour means the same role on every page in the Lab.
Examples in context
Real-world sentences, easiest first. Toggle pinyin or the translation, tap any word to see its role, or play the audio.
Tap a word to see its grammatical role.
xiǎo gǒu de ěrduo 小狗的耳朵 Subject cháng 长 Adjective cháng 长 Adjective de 的 Function word
The puppy’s ears are nice and long (AA + 的).
zhè bēi chá 这杯茶 Subject rè 热 Adjective rè 热 Adjective de 的 Function word hěn shūfu 很舒服 Adjective
This cup of tea is nice and warm — very comforting (AA + 的).
wǒ 我 Subject xǐhuan 喜欢 Verb gāngān-jìngjìng 干干净净 Adjective de 的 Function word fángjiān 房间 Object
I like a spotlessly clean room (AABB + 的 + noun).
wǒ 我 Subject xiǎng yào 想要 Verb yí gè 一个 Measure word jiǎnjiǎn-dāndān 简简单单 Adjective de 的 Function word hūnlǐ 婚礼 Object
I want a nice simple wedding (AABB + 的 + noun).
háizimen 孩子们 Subject kāikāi-xīnxīn 开开心心 Adjective de 地 Function word wán 玩 Verb le 了 Function word yí xiàwǔ 一下午 Time
The kids played happily all afternoon (AABB + 地 + verb).
tā 他 Subject rènrèn-zhēnzhēn 认认真真 Adjective de 地 Function word xiě wán 写完 Verb le 了 Function word zuòyè 作业 Object
He did his homework carefully and thoroughly (AABB + 地 + verb).
gōngzuò le yì zhōu 工作了一周 Time zhōumò 周末 Time gāi 该 Function word fàngsōng 放松 Verb fàngsōng 放松 Verb le 了 Function word
After a week of work, the weekend’s for unwinding (ABAB as a predicate, verb-like).
tiān 天 Subject yīn 阴 Adjective yīn 阴 Adjective de 的 Function word kàn qǐlái 看起来 Verb yào 要 Function word xià yǔ 下雨 Verb le 了 Function word
The sky’s all grey — looks like rain (AA + 的, with the “about to” 要…了).
Common mistakes
Why it happens: Two-syllable ADJECTIVES double each character — AABB: 干干净净, 高高兴兴. The whole-word ABAB (干净干净) belongs to verbs (研究研究), not adjectives. It’s the exact mirror.
Why it happens: Before a noun it ends in 的 (干干净净的房间); used as an adverb before a verb it ends in 地 (认认真真地写). Same sound, different character — 的 for nouns, 地 for verbs.
Why it happens: Not every adjective reduplicates — mostly the vivid, descriptive ones. 好吃, 便宜, 麻烦 don’t take AABB (好好吃吃 ✗). When unsure, just use 很 + adjective (很好吃).
Compare & contrast
| Adjective → AABB (each char doubles) | Verb → ABAB (whole word repeats) | The difference |
|---|---|---|
| 高高兴兴gāogāo-xìngxìng | 研究研究yánjiū yánjiū | 高高兴兴 (“happy”) is an adjective — each character doubles. 研究研究 (“look into it”) is a verb — the whole word repeats. AABB vs ABAB. |
| 干干净净gāngān-jìngjìng | 讨论讨论tǎolùn tǎolùn | 干干净净 (“clean,” adjective, AABB) vs 讨论讨论 (“discuss,” verb, ABAB). The word class decides the pattern. |
Try it yourself
Say “The grass is nice and green.” — double the one-syllable adjective, then 的.
Related patterns
Quick reference card
Reduplication of Adjectives (红红的, 高高兴兴的) grammar.merrymandarin.com A pocket summary — print it and keep it by your desk.