如果句子的謂語本身含有be動詞,直接在be後加not即可。例如:
She is goot at science.改為否定:She is not(isn"t) good at science.
She is reading a book.改為否定:She isn"t reading a book.
如果句子的謂語含有助動詞have(用於完成時。注意是助動詞,不是實意動詞),直接在have後面加not即可。例如:
She has read this book.改為否定:She has not(hasn"t) read this book.
She had finished the housework when I came back home.改為否定:She hadn"t finished the housework when i came back home.
當句子含有情態動詞時(can, could,must, should, shall, will, would, may,might等),直接在情態動詞後加not。例如:
You can do it tomorrow.改為否定:You can"t do it tomorrow.
但需注意,情態動詞must表示必須做某事的時候,其否定不用mustn"t(mustn"t表示一定不能,而不是“不必”,而應該用needn"t)。如:
Must i finish the task today?——No, you needn"t.我必須今天完成任務嗎?——不,不必今天。
如果陳述句是除了上述的情況以外的,也就是說句子的謂語不含有be、have、情態動詞,而是其他實意動詞時,改成否定就需要在動詞前補充助動詞do(需要根據時態和人稱變換),然後再加not。
例如:
She likes reading books.改為否定:She does not like reading books.(此時還需注意,likes改為否定句時,應用動詞原形)
She went shopping yesterday. 改為否定:She did (過去時)not go shopping yesterday.(went同樣要改為原形)
They like reading books.改為否定:They do not (don"t) like reading books.
如果句子的謂語本身含有be動詞,直接在be後加not即可。例如:
She is goot at science.改為否定:She is not(isn"t) good at science.
She is reading a book.改為否定:She isn"t reading a book.
如果句子的謂語含有助動詞have(用於完成時。注意是助動詞,不是實意動詞),直接在have後面加not即可。例如:
She has read this book.改為否定:She has not(hasn"t) read this book.
She had finished the housework when I came back home.改為否定:She hadn"t finished the housework when i came back home.
當句子含有情態動詞時(can, could,must, should, shall, will, would, may,might等),直接在情態動詞後加not。例如:
You can do it tomorrow.改為否定:You can"t do it tomorrow.
但需注意,情態動詞must表示必須做某事的時候,其否定不用mustn"t(mustn"t表示一定不能,而不是“不必”,而應該用needn"t)。如:
Must i finish the task today?——No, you needn"t.我必須今天完成任務嗎?——不,不必今天。
如果陳述句是除了上述的情況以外的,也就是說句子的謂語不含有be、have、情態動詞,而是其他實意動詞時,改成否定就需要在動詞前補充助動詞do(需要根據時態和人稱變換),然後再加not。
例如:
She likes reading books.改為否定:She does not like reading books.(此時還需注意,likes改為否定句時,應用動詞原形)
She went shopping yesterday. 改為否定:She did (過去時)not go shopping yesterday.(went同樣要改為原形)
They like reading books.改為否定:They do not (don"t) like reading books.