HSK 4 grammar · pattern
一A一B
一A一B — a matched pair (one…, one…)
Pattern
+ + +
A and B are one-syllable words of the same kind
( ) can be left out · other words may come before, between and after
How it works
一A一B places two parallel one-syllable words into 一…一… to picture two matching parts or alternating actions — 一问一答 "one asks, one answers", 一高一低 "one high, one low". It paints a balanced, paired image.
Examples
他们俩一问一答，很有意思。
Tāmen liǎ yí wèn yì dá, hěn yǒu yìsi.
The two of them, one asking and one answering, are quite amusing.
这两座楼一高一低。
Zhè liǎng zuò lóu yì gāo yì dī.
These two buildings are one tall, one short.
桌上的花瓶一大一小。
Zhuō shàng de huāpíng yí dà yì xiǎo.
The vases on the table are one big, one small.
Related
See it in a story
In the app, 一A一B is underlined wherever it appears in the stories you read, and practised with sentences from them. Free.