动词不定式

　　( 1)作主语

　　To learn a foreign language is not easy.

　　It is not easy to learn a foreign language.

　　( 2)作宾语

　　They began to read.

　　( 3)作宾语补足语

　　Jim asked me to help him with his lessons.

　　We often heard her sing.

　　( 4)作定语

　　I have an important meeting to attend.

　　( 5)作状语

　　She went to see her grandma yesterday.

　　( 6)用在how, when, where, what, which等之后

　　I don’t know how to use a computer.

　　Do you know when to start?

　　He didn’t know what to do next.

　　句子种类

　　(1)陈述句 ( 肯定式和否定式)

　　(2)疑问句 ( 一般疑问句、特殊疑问句、选择疑问句、反意疑问句)

　　(3)祈使句 ( 肯定式和否定式)

　　(4)感叹句

　　句子成份

　　1)主语

　　Betty likes her new bike.

　　He gets up early every day.

　　To learn a foreign language is not easy.

　　2)谓语

　　We work hard.

　　The boy caught a bird.

　　He is my brother.

　　They all look fine.

　　3)表语

　　Her sister is a nurse.

　　It’s me. I’m ready.

　　He got angry.

　　We were at home last night.

　　His cup is broken.

　　4)宾语

　　Tom bought a story-book.

　　I saw him yesterday.

　　He wanted to have a cup of tea.