根据英语词汇在英语句子中的地位和作用，英语句子的成分可分为主语、谓语、宾语、表语、定语、状语、补语，此外还有同位语、插入语及呼语。一、主语主语是句子的主体，是要说明的人或事物。主语常由名词、代词、数词、名词化的形容词、动词不定式、动名词、从句等充当。如：Lily likes her new bike. (名词)Eight is a lucky number in China. (数词)To learn English well is not easy. (不定式短语)注意：当动词不定式、动名词、从句等作主语时，为了避免头重脚轻的情况，常在句首用it作形式主语，而把真正的主语放在句尾。二、谓语谓语是说明主语“做什么”、“是什么”或“怎么样”的，由动词或动词短语充当。谓语有人称、数、时态和语态的变化。如：The train leaves at 10:15. All my classmates work hard. The man caught a bird in the tree. 三、宾语宾语在句中主要充当动作的承受者。宾语通常由名词、代词、数词、名词化的形容词、不定式、动名词、从句等充当。My sister bought some apples yesterday.(名词)They wanted to have a rest after the long walk. (不定式短语)The student from the north enjoys eating noodles.(动名词短语)注意：有些及物动词可以有两个宾语，一个指人，一个指物。My uncle gave me an interesting magazine.四、表语
表语是用来说明主语的身份、性质、品性、特征和状态的，常位于系动词之后，由名词、代词、形容词、数词、副词、介词短语、不定式、动名词、分词、从句等来充当。常见的系动词有：be, become, appear, seem, look, sound, feel, get, smell等。如：
His brother is a doctor. (名词)The old man got angry when he heard the news. (形容词)五、定语定语是用来修饰、限制名词或代词的句子成分，由形容词、名词、代词、数词、副词、不定式、动名词、分词、介词短语和从句等充当。如：Put it in the top drawer. (形容词)He is not only an actor but also a collegeteacher. (名词)I have an important meeting to attend this afternoon. (不定式)注意：形容词作定语时通常放在被修饰的词之前，而介词短语、不定式短语或副词等作定语时通常放在被修饰的词之后。六、状语状语用于修饰动词、形容词、副词或整个句子，一般由副词、介词短语、非谓语动词短语或从句等充当。如：I’m very glad to meet you here. (副词)My brother goes to school by bike. (介词短语)You can’t leave until your work is finished.(从句)七、补语补语分为主语补语和宾语补语。补语是起补充说明作用的成分。最常见的是宾语补足语，由形容词、名词、副词、非谓语动词和介词短语等来充当。如：You should not call the boy a fool. (名词)We must keep our classroom clean and tidy.(形容词)
即学即练
请用句子成分符号标出下列句子的成分。1. Failure is the mother of success.2. We had different students in some classes. 3. She danced for joy. 4. My brother began learning English five years ago. 5. The president will visit our company next week.【参考答案】
