如果句中的主语与动词距离很大，句子通常会显得不自然而且难以理解。以下将具体说明这类问题所产生的典型情况。
- This solution, which was first derived by Wallace in an investigation of excitable media, has three critical points.
(1) This solution was first derived by Wallace in an investigation of excitable media. It has three critical points.
(1’) This solution has three critical points. It was first derived by Wallace in an investigation of the excitable media. - The work of Tenna et al. [14], in which the effectiveness of a new method for precisely measuring the error rate in protein synthesis is demonstrated, has been cited as a success of the new phenomenological approach.
(2) Tenna et al. [14] have demonstrated the effectiveness of a new method for precisely measuring the error rate in protein synthesis. That work has been cited as a success of the new phenomenological approach. - A detailed analysis is given in Section 4, in which the convexity of the intersection of the sets S and T in the present case is demonstrated.
(3) A detailed analysis is given in Section 4, in which it is demonstrated that the intersection of the sets S and T is convex in the present case.
上述各原句都以不同的方法修改过。在例句(1)中，关系代词从句 which… 修饰主语 solution，因此必须放在主语与动词之间；而例句(1)及(1’)，则将例句(1)拆成两个句子来解决上述问题。在这两种解决方法中，句子都变得更流畅自然、更容易理解，而且表达的意思与原句相同。在例句(2)中，两组主语 + 动词有问题；一组是 work 与 has been cited，另一组是 effectiveness 与 is demonstrated。第一组的问题是，两者之间出现很长的关系副词从句 in which…；这个问题可采用与例句(1)相同的方法来解决，即将原句拆为两句。为了解决第二组的问题，可将例句(2)的被动语态改为主动语态，并将主语从 effectiveness 改为 Tenna et al.。在类似例句(3)的情况下，最理想的解决方法是使用包含虚主语的结构；这种结构以例句(3)为代表，其虚主语为 it。
