从语法规则来看，代名词应该指代单一、明确描述的先行词，并且应该保持与先行词在数量上的一致性。在我的学术编辑经历中，几乎每一篇文章都存在或多或少的违反此语法规则的情形，举例如下：
The ZnO peaks for the samples that were dried for 5 days are smaller than that for the sample that was dried immediately.
单数指示代名词that必须跟单数的先行词，但是上面的句子中却错误使用that指代前面的复数名词the ZnO peaks。又例如：
The molar ratio in these complexes was smaller than those in the previously synthesized complexes.
此句中，作者使用复数指示代名词those指代其所隐含的molar ratios，但有些读者可能会误以为those指代的是较靠近的复数名词complexes。幸好，有个简单但稍微费字的方法可以修正这类句子：将代名词用指代的名词或名词词组来替换。
The molar ratio in these complexes was smaller than the ratios in the previously synthesized complexes.
另举三个类似的例句，其中推荐的修改以斜体表示：
原句：The line shape of the band of the heterotrinuclear complex was intermediate between those of the homotrinuclear complexes.
改句：The line shape of the band of the heterotrinuclear complex was intermediate between the line shapes of the homotrinuclear complexes.
原句：In the homozygous mutant seeds, the fluorescence intensity in the rER was as weak as those in the amyloplasts.
改句：In the homozygous mutant seeds, the fluorescence intensity in the rER was as weak as the intensities in the amyloplasts.
原句：The massic activities of 210Pb in soils, fly ash, and coal were compared with that in aerosols.
改句：The massic activities of 210Pb in soils, fly ash, and coal were compared with the massic activity in aerosols.
在学术写作里，清晰的语意有时比简洁的文笔来得更重要。
