对称的平行结构词组
同一名词在介词之后的再次出现，构成的词组被称为平行结构词组。例如：face to face，day after day。此类词组通常具有副词功能。现举例归纳如下。
一、表示时间
1．day after day 一天又一天地
2．day by day 一天天地
3．year after year 一年又一年
4．year by year 一年年地
She studied hard day after day， until she could master the subject．她日复一日地努力钻研，直到完全掌握那门学科为止。
The boy grows taller year by year．这男孩长得一年比一年高了。
二、表示次数
如time after time再三；几次三番
I've told him time ofter time not to touch my papers．我已经跟他说了不知多少次，叫他别动我的文件。
三、表示渐进
1．little by little 逐渐地
2．one by one 一个一个地；逐一地
3．step by step 一步一步地；逐步地
4．bit by bit 一点一点地；逐渐地
5．word for word 逐字地；一字不改地
6．inch by inch 一点一点地；逐渐地
The students entered the classroom one by one．学生们一个个地走进教室。
Step by step，I came near the first building．我一步一步地走近第一座楼房。
Bit by bit，she closed the gap．她一点一点地缩短了差距。
Please repeat the statement word for word．请把声明逐字逐句地复述一遍。
四、其他
1．all in all 最钟爱者；总而言之；心目中的一切
2．end to end 两端相接
3．end for end 两端的位置颠倒过来
They are all in all to each other．他们彼此亲密无间。
At the factory，we saw hundreds of tractors lined up end to end．在厂里我们看到几百台拖拉机首尾相接地排着。
When we turned the stone end for end，it fitted nicely into the gap．我们把石头倒过来放，正好把缝塞住了。