1. be動詞，既可以是聯絡動詞，也可以是助動詞。❶ 聯絡動詞，後接名詞、非謂語動詞、形容詞、數詞、代詞、副詞、介詞等作表語，且有各種時態變化：一般現在時am\is\are\一般過去時was\werer完成時has\have\had\been將來時用be原形現在分詞being過去分詞been沒有被動語態He is a well-known artist.他是一位著名的藝術家。(名詞)The student has been here for hours.這個學生來這裡好幾個小時了。(副詞)My ambition is to become a scientist when I grow up.我的大志就是長大當科學家。(不定式)When he was eleven, he graduated from that school.他11歲時就從那所學校畢業了。(數詞)❷ 助動詞，用於進行時和被動語態。進行時：現在進行時am\is\are+現在分詞過去進行時was\were+現在分詞將來進行時助動詞+be+現在分詞完成進行時助動詞+been+現在分詞He is reading now.他在看書。I was doning my housework when he came.他來的時候我在做家務活。He has been learning English ever since last year.從去年到現在他一直在學英語。被動語態：一般現在時am\is\are+過去分詞一般過去時was\were+過去分詞將來時助動詞+be+過去分詞完成時助動詞+been+過去分詞進行時只有現在進行時和過去進行時才有被動語態：現在進行時am\is\are+being +過去分詞過去進行時was\were+being +過去分詞The room is cleaned every day.房子每天打掃。He was criticized yesterday by his teacher.他昨天挨他老師批評了。The building is being built now by the builders.建築工人正在建這棟建築物。The machine has been fixed, working properly again.進去修好了，又在正常運轉中。
2. do作為助動詞，用於一般現在時的否定句、疑問句中，肯定陳述句不出現。有時也用於肯定陳述句中對謂語動詞進行強調。祈使句中也用do表示強調或表示否定。一般現在時第三人稱單數要用does形式。He doesn"t get up early every day.他每天起床不早。Do you often go shopping after breakfast every morning? 你每天上午吃早飯後去購物嗎？Do sit down please.請坐！Don"t sit here doing nothing.別坐在這裡無所事事。He often does work hard every day.他每天的確努力工作。
它們有本質區別。
1. be動詞，既可以是聯絡動詞，也可以是助動詞。❶ 聯絡動詞，後接名詞、非謂語動詞、形容詞、數詞、代詞、副詞、介詞等作表語，且有各種時態變化：一般現在時am\is\are\一般過去時was\werer完成時has\have\had\been將來時用be原形現在分詞being過去分詞been沒有被動語態He is a well-known artist.他是一位著名的藝術家。(名詞)The student has been here for hours.這個學生來這裡好幾個小時了。(副詞)My ambition is to become a scientist when I grow up.我的大志就是長大當科學家。(不定式)When he was eleven, he graduated from that school.他11歲時就從那所學校畢業了。(數詞)❷ 助動詞，用於進行時和被動語態。進行時：現在進行時am\is\are+現在分詞過去進行時was\were+現在分詞將來進行時助動詞+be+現在分詞完成進行時助動詞+been+現在分詞He is reading now.他在看書。I was doning my housework when he came.他來的時候我在做家務活。He has been learning English ever since last year.從去年到現在他一直在學英語。被動語態：一般現在時am\is\are+過去分詞一般過去時was\were+過去分詞將來時助動詞+be+過去分詞完成時助動詞+been+過去分詞進行時只有現在進行時和過去進行時才有被動語態：現在進行時am\is\are+being +過去分詞過去進行時was\were+being +過去分詞The room is cleaned every day.房子每天打掃。He was criticized yesterday by his teacher.他昨天挨他老師批評了。The building is being built now by the builders.建築工人正在建這棟建築物。The machine has been fixed, working properly again.進去修好了，又在正常運轉中。
2. do作為助動詞，用於一般現在時的否定句、疑問句中，肯定陳述句不出現。有時也用於肯定陳述句中對謂語動詞進行強調。祈使句中也用do表示強調或表示否定。一般現在時第三人稱單數要用does形式。He doesn"t get up early every day.他每天起床不早。Do you often go shopping after breakfast every morning? 你每天上午吃早飯後去購物嗎？Do sit down please.請坐！Don"t sit here doing nothing.別坐在這裡無所事事。He often does work hard every day.他每天的確努力工作。