HSKReadyGet the appHSK 4 Fixed Phrase: 一 + Measure Word + 比 + 一 + Measure Word
The fixed phrase 一 + 量词 + 比 + 一 + 量词 compares successive units of time, actions, or objects to show that a quality increases or changes step by step.
春天到了，天气一天比一天暖和。
Uses the time measure word 天 (day) to show gradual change over successive days.
× 他的汉语水平一年比一年很好。
Incorrect: In a 比 comparative structure, the degree adverb 很 cannot be placed before the adjective 好. Replace this with the corrected sentence.
Corrected example: 他的汉语水平一年比一年好。
Read the full explanation and examples
What This Fixed Phrase Means
In Mandarin, the fixed phrase 一 + 量词 + 比 + 一 + 量词 (yī + measure word + bǐ + yī + measure word) is a comparative pattern listed under Level 4 fixed formats in the supplied HSK outline. Literally, it states that one unit is more of a certain quality than the previous unit. In natural English, it translates to expressions such as day by day, year after year, or one after another.
This pattern serves two closely related communicative functions depending on the type of measure word you choose. When used with a time or event measure word, it describes a steady trend over time. When used with a nominal measure word that classifies people or objects, it compares members of a group in sequence, emphasizing that each item surpasses the last or that the entire group shares a high degree of the quality.
Sentence Structure and Measure Word Choice
The two measure words on either side of 比 must be identical. The entire 一 + 量词 + 比 + 一 + 量词 chunk sits directly before the predicate—most commonly an adjective—acting as an adverbial modifier that shows how the quality develops.
春天到了，天气一天比一天暖和。
Uses the time measure word 天 (day) to show gradual change over successive days.
考试的题目一道比一道难。
Uses 道, the specific measure word for exam questions, to compare items in sequence.
- Time words such as 天 (day) and 年 (year) go directly into this slot without 个: 一天比一天 and 一年比一年.
- Verbal measure words for occurrences—such as 次 (cì, time/occurrence) or 遍 (biàn, time through)—track improvement or change across repeated actions: 一次比一次 (each time more than the last).
- Nominal measure words must match the subject noun being compared. Because 题目 (tímù, test questions) takes 道 (dào), the phrase becomes 一道比一道; for people or general items taking 个 (gè), it becomes 一个比一个.
Using Verbal Predicates and Complements
Although simple adjectives are the most frequent predicates in this pattern, you can also use mental verbs, adjectives that behave like stative verbs, or verb phrases containing a degree complement (得). The key requirement is that the predicate must describe a gradable state or performance that can differ in degree.
比赛的时候，运动员们一个比一个跑得快。
跑得快 supplies the gradable performance. 一个比一个 can be emphatic praise of the group rather than a measured ranking or a claim that each runner speeds up over time.
这几个孩子一个比一个懂事。
Shows that a gradable stative verb or adjective like 懂事 works naturally after the comparison.
When speakers say 一个比一个 plus a positive trait like 懂事 (dǒngshì, sensible) or 跑得快 (pǎo de kuài, run fast) about a group of people, they do not necessarily mean they measured everyone in strict numerical order. In everyday conversation, it often serves as an emphatic way to say that every single person in the group is remarkably sensible or fast.
Contrast: 一 + 量词 + 比 + 一 + 量词 vs. 越来越
Learners often wonder how this fixed phrase differs from 越来越 (yuè lái yuè, more and more), since both describe progressive change. While their meanings overlap when talking about time, they are not always interchangeable.
- Explicit unit: 一天比一天 or 一次比一次 names the units being compared. 越来越 highlights a developing trend without naming each unit; the progression may be over time, a sequence of items, or movement through space.
- Different dishes: 一道比一道好吃 explicitly compares successive dishes. Later dishes can also be described as 越来越好吃 while they are served or tasted in sequence; that does not require one dish itself to improve. For a group with no intended sequence, 一个比一个 often stresses that all members have the quality.
Common Learner Mistake and Limits
In the basic comparative predicate, do not put 很 or 非常 directly before 好: use 一年比一年好, not 一年比一年很好. To express the speaker’s reaction to the whole claim, 真 can occur elsewhere, as in 这些题真是一个比一个难. This does not license 一年比一年真好 as the same basic comparison.
× 他的汉语水平一年比一年很好。
Incorrect: In a 比 comparative structure, the degree adverb 很 cannot be placed before the adjective 好. Replace this with the corrected sentence.
Corrected example: 他的汉语水平一年比一年好。
他的汉语水平一年比一年好。
Correct replacement: The adjective 好 stands directly after 一年比一年 without 很.
Frequently asked questions
Can the two measure words in 一 + 量词 + 比 + 一 + 量词 be different?
No. In this fixed phrase, the measure word after the first 一 and the measure word after the second 一 must be the exact same word, because you are comparing units of the same kind.
Can I omit the second 一 after 比?
The full model repeats 一 in both places and is the clearest form to learn first. Some colloquial time expressions shorten the second unit, as in 一天比天热. Do not treat the full form as a rule that every shortened version is ungrammatical.
Can I put a simple action verb right after this phrase?
Not by itself. Because 比 expresses a comparison of degree, the predicate must be gradable—such as an adjective, a mental verb, or an action verb paired with a degree complement like 得快 or 得多.
