两个或两个以上简单句（Simple Sentence）可以合成一个较长的简单句、并列句（Compound Sentence）或复杂句 （Complex Sentence）．通过句子的合成，我们得以更清楚地看出句子间的语义关系，而且还可以使句子多样化，增加文章的丰姿。
现在就从三方面来看看句子合成法的问题。
1．由两三个简单句合成一个长的简单句。例如：
（1） John ran away． He escaped the danger． → Running away， John escaped the danger．）
（2） The hunter took up his gun． He shot the boar．→ The hunter took up his gun to shoot the boar．
（3） The king died． The queen heard about it． She fainted．→ On hearing about the king's death， the queen fainted．
（4） Kelvin is my good friend． He is a strong supporter of social justice．→ Kelvin， a strong supporter of social justice， is my good friend．
（5） The rascal kicked the cat． He kicked it on the back． He kicked it intentionally．→ The rascal kicked the cat on the back intentionally．
2．由两三个简单句合成一个并列句。例如：
（6） John was sad． He kept quiet．→ John was sad but he kept quiet．
（7） Take the book． Leave it there．→ Take the book or leave it there．
（8） Sean did not come to class today． He had a bad headache．→ Sean did not come to class today， for he had a bad headache．
（9） Bruce was lying on the bed． He looked at the ceiling． He saw a lizard．→ Lying on the bed， Bruce looked at the ceiling and saw a lizard．
3．由两三个简单句合成一个复杂句。例如：
（10） Kelvin is getting rich． We know about it．→ We know that Kelvin is getting rich．
（11） I like this book． It contains many amusing stories．→ I like this book which contains many amusing stories．
（12） Helen is sure to get her pay． It is due to her． Why does she complain? → Why does Helen complain since she is sure to get the pay due to her ?
（13） The woman was exhausted． She had not slept well the previous night．→ The woman was exhausted because she had not slept well the previous night．
上面例子显示，简单句由“主语＋谓语”（Subject ＋ Predicate）构成，有时还附有修饰性的短语。并列句由至少两个地位平等的并列分句透过并列连词（Coordinating Conjunction）如“ and， or， but， so， for ”等连成。复杂句包括一个主句（Main Clause）及至少一个从句（Subordinate Clause），通过从属连词 （Subordinating Conjunction）如 “That， since， because， when， if ”等合成。从属分句因功能不同而分成“名词从句”（Noun Clause），“副词从句”（Adverb Clause）和“形容词从句” （Adjective Clause）．上述诸句式中，复杂句最为多采多姿，不妨多用。为了避免句子太长，难以控制，一个复杂句最好不要超过三个从句。
（责任编辑:秩名）
