名人教英文：关系子句（relative clause）
英语文法中，一个简单句只能有一个主要动词。譬如说，this is a dog likes ice-cream一句内，有is和likes两个主要动词，便错了。
我们可以把这话改为复句：this is a dog which likes ice-cream。which为「关系代词」（relative pronoun），而which likes ice-cream叫「关系子句」（relative clause），作用是修饰名词dog。
除了which之外，who、whom和that都是常用的关系代词。
最近，汇贤通识学苑暑期班的学生撰文议论外佣居留权问题。我批改文章时，发现不少学生犯了上述错误，以下两个经过改写的例子：
例子一：
there will be about a hundred thousand foreign domestic helpers can become permanent residents of hong kong if the government loses the lawsuit.
there will be about a hundred thousand foreign domestic helpers can become permanent residents of hong kong这部分，有will be和become两个动词。一个改正方法是加上关系代词who： there will be about a hundred thousand foreign domestic helpers who can become permanent residents of hong kong...
此外，there will be … who … 句式冗赘。为求简洁，不如把整句改成：about a hundred thousand foreign domestic helpers can become permanent residents of hong kong if the government loses the lawsuit.
又例如文章开首的例子，可改为this dog likes ice-cream。
例子二：
during the hostage crisis happened in manila, i got to know that hong kong was dubbed "the city of domestic helpers".
the hostage crisis happened in manila是完整句子，但during是介词（就像in、at、on等），只能配以名词或名词短语，不能连接句子。
要改正这句，可以使用关系代词which：during the hostage crisis which happened in manila, i got to know that hong kong was dubbed "the city of domestic helpers".
the hostage crisis which happened in manila是名词短语，关系子句which happened in manila是名词hostage crisis的修饰语。其实，再简单一点，可以说the hostage crisis in manila甚或the manila hostage crisis。
要写好复句，必先掌握文法结构；而现代英语写作贵乎平易畅达，简单句往往更能达意。
英语单词词汇学习：
lawsuit……诉讼
hostage crisis……人质危机
dub……给…取绰号