完整句和不完整句

一個語法結搆完整的句子至少有一個主語和一個謂語動詞；如果是及物動詞，還得有一個賓語；如果是系動詞，則必須有一個表語或補語：

　　He won.

　　I owe you.

　　John is late.

　　定語和狀語雖不是句子中不可缺少的成分，但有助於表達清楚或完整的意思：

　　He won an easy victory.

　　I owe you.

　　John is late again.

　　需要注意的是：一個完整的句子以大寫字母開始，以句號結束。寫英文時用逗號代替句號、分號、冒號或破折號叫“逗號錯”，這正是中國學生所要避免的。請比較下列例句：

　　誤：It was raining hard, they could not work in the fields.

　　正：It was raining hard; they could not work in the fields.

　　It was raining hard. They could not work in the fields.

　　It was raining so hard that they could not work in the fields.

　　They could not work in the fields because it was raining hard.

　　It was raining hard, so they could not work in the fields.

　　As it was raining hard, they could not work in the fields.

　　誤：The essay is poorly organized, there is no central idea.

　　正：The essay is poorly organized; there is no central idea.

　　The essay is poorly organized: there is no central idea.