HSK 4
一A一B
yī A yī B
The structure '一A一B' emphasizing detail, specificity
Explanation
一A一B is a four-character idiomatic form (四字格 sìzìgé — a fixed four-character phrase); A and B are usually two small nouns, placed between two occurrences of 一 yī (one) to emphasize meticulousness, thoroughness, and leaving nothing out.
一 yī + A + 一 yī + B, with the whole phrase functioning as a fixed idiom, often serving as an adverbial (a component indicating manner) together with 地 de and placed before the verb.
when you want to express doing something very carefully and in detail, or "not even the smallest thing is overlooked". For example, 一针一线 yī zhēn yī xiàn (one needle one thread) = everything, however small; 一五一十 yī wǔ yī shí = to recount every detail clearly.
these are fixed phrases; you may not arbitrarily replace A and B with other nouns as you please.
translating machine-like word by word (一五一十 is not "one five one ten"); you need to understand the whole phrase as an idiom with a figurative meaning.
Examples
These are other people's belongings; we must not take even a single needle or thread.
He reported the situation to the teacher in full detail, without leaving anything out.
Practice
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Learn “一A一B” effectively
The grammar point “一A一B” (The structure '一A一B' emphasizing detail, specificity) is one of the key structures at HSK 4. To use it fluently, you need to understand the contexts where it's used and practice regularly.
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