4.悬垂修饰语（Dangling Modifiers)
所谓悬垂修饰语是指句首的短语与后面句子的逻辑关系混乱不清。如：
(1 )At the age of ten，my grandfather died.
本句中at the age of ten只点出十岁时，但没有说明“谁”十岁时。按一般推理不可能是主句主语my grandfather，如果把这个悬垂修饰语改明确一点，全句就不那么费解了。
改为：When I was ten, my grandfather died.
(2 )To do well in college, good grades are essential.
本句中不定式短语“to do well in college"的逻辑主语不清楚。
改为：To do well in college, a student needs good grades.
(3 )Having finished the assignment，the TV was turned on.
本句中，英语的正确表达方式要求现在分词的逻辑主语应该为主句主语，但从上面句子我们可以 看到 having finished the assignment的逻辑主语不可能为the TV，句子错误。
改为：Having finished the assignment, Jill turned on the TV.

5.词性误用（Misuse    of Parts of Speech)
“词性误用”常表现为:介词当动词用;形容词当副词用;名词当动词用，等等。如：
(1 )None can negative the importance of money.
本句中negative是形容词，不能作为谓语动词使用。
改为：None can deny the importance of money.
(2 )Some people against the idea.
本句中against是介词，不能用作动词。
改为：Some people are against the idea.
(3 )As a result of it rained heavily, people had to stay indoors.
上句中of是介词，不能用作连词。
改为：As a result of the heavy rain, people had to stay indoors.

6. 指代不清（Ambiguous Reference of Pronouns)
指代不清主要指的是代词与被指代的人或物关系不清，或者先后所用的代词不一致。
(1 ) Mary was friendly to my sister because she wanted her to be her bridesmaid.
读完上面这句话,读者无法明确地判断两位姑娘中谁将结婚，谁将当伴娘。如果把易于引起误解 的代词的所指对象加以明确，意思就一目了然了。
改为：Mary was friendly to my sister because she wanted my sister to be her bridesmaid.
(2 )We can also know the society by serving it yourself.
本句中人称代词we和反身代词yourself指代不一致。
改为：We can also know society by serving it ourselves.
(3 )People have been fighting against the environmental pollution，but it often proves useless.
本句中it指代不明确，可以用which引导定语从句的结构来表达。
改为：People have been fighting against the environmental pollution, which often proves useless.