名词、量词和数量词短语的重叠

The reduplication of nouns, measure words, and numeral-measure word phrases
Some reduplicated nouns and measure words denote the inclusion of the entirety without exception and are often used as subjects or attributes. Foe example,
现在人人都关心北京的绿化。
他们个个都喜欢用筷子。
件件衣服都小了。
篇篇文章都写得很好。

Note: Reduplicated nouns and measure words cannot be used as the objects or attributes of objects. For example, one cannot say：“ 我告诉人人。“”我喜欢张张照片。“
Reduplicated time words can be used as adverbials. For example,
他天天听都打太极拳。
他去博物馆参观了很多次，次次都觉得很有意思。

Reduplicated numeral-measure word phrase, mainly of the reduplicated pattern of “一 +M” , are used as adverbials that denote the manner of an action, meaning “one after another”. “地” must be added at the end of the phrase. For example,
我们一步一步地往上爬吧。（step by step）
我们的汉语水平正一天一天地提高。（day after day）
他一张一张地把照片给大家看。(one by one)
小学生排着队，两个两个地走进餐厅。（two by two）

Reduplicated numeral-measure word phrases are used as the attributes that denote the description of something, meaning “many” or “every”. “的” must be added at the end of the phrase. For example,
一棵一棵的小树种得多整齐啊！
一盘一盘的水果就放在桌子上。
一个一个的问题都回答对了。