一個(gè)語(yǔ)法結(jié)構(gòu)完整的句子至少有一個(gè)主語(yǔ)和一個(gè)謂語(yǔ)動(dòng)詞；如果是及物動(dòng)詞，還得有一個(gè)賓語(yǔ)；如果是系動(dòng)詞，則必須有一個(gè)表語(yǔ)或補(bǔ)語(yǔ)：
He won.
I owe you.
John is late.
定語(yǔ)和狀語(yǔ)雖不是句子中不可缺少的成分，但有助于表達(dá)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(gè)完整的句子以大寫字母開始，以句號(hào)結(jié)束。寫英文時(shí)用逗號(hào)代替句號(hào)、分號(hào)、冒號(hào)或破折號(hào)叫“逗號(hào)錯(cuò)”，這正是中國(guó)學(xué)生所要避免的。請(qǐng)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.
He won.
I owe you.
John is late.
定語(yǔ)和狀語(yǔ)雖不是句子中不可缺少的成分，但有助于表達(dá)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(gè)完整的句子以大寫字母開始，以句號(hào)結(jié)束。寫英文時(shí)用逗號(hào)代替句號(hào)、分號(hào)、冒號(hào)或破折號(hào)叫“逗號(hào)錯(cuò)”，這正是中國(guó)學(xué)生所要避免的。請(qǐng)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.