主謂一致

doing eye exercises is good for your eyes.
做眼睛保健操對你的眼睛十分有益。因此在實際操練中要指導學法，掌握基本用法，注意變化就能突破。
【知識網絡】                   主謂一致用法
在英語句子里，謂語受主語支配，其動詞必須和主語在人稱和數上保持一致，這就叫主謂一致。尋其規律，大致可歸納為三個原則，即語法一致、邏輯意義一致和就近一致原則。
（一）語法一致原則：語法上一致就是謂語動詞和主語在單、復數形式上保持一致。
1、以單數名詞或代詞、動詞不定式短語、動名詞短語或從句作主語時，謂語動詞一般用單數形式；主語為復數時，謂語動詞用復數形式。
his father is working on the farm. / to study english well is not easy. / what he said is very important for us all. / the children were in the classroom two hours ago. / reading in the sun is bad for your eyes.
注意：由what引導的主語從句，后面的謂語動詞多數情況用單數形式，但若表語是復數或what從句是一個帶有復數意義的并列結構時，主句的謂語動詞用復數形式。
what i bought were three english books. / what i say and do is (are) helpful to you.
2、由連接詞and或both ... and連接起來的合成主語后面，要用復數形式的謂語動詞。如：lucy and lily are twins. / she and i are classmates. / the boy and the girl were surprised when they heard the news. / both she and he are young pioneers.
注意：① 若and所連接的兩個詞是指同一個人或物時，它后面的謂語動詞就應用單數形式。如：the writer and artist has come.; / ② 由and連接的并列單數主語前如果分別有no, each, every more than a (an) , many a (an)修飾時，其謂語動詞要用單數形式。如：every student and every teacher was in the room.. / no boy and no girl likes it.
3、主語為單數名詞或代詞，盡管后面跟有with, together with, except, but, like, as well as, rather than, more than, no less than, besides, including等引起的短語，謂語動詞仍用單數形式；若主語為復數，謂語用復數形式。如：mr green, together with his wife and children, has come to china. / nobody but jim and mike was on the playground. / she, like you and tom, is very tall.
4、either, neither, each, every 或no +單數名詞和由some, any, no, every構成的復合不定代詞，都作單數看待。如：each of us has a new book. / everything around us is matter.
注意：① 在口語中當either或neither后跟有"of+復數名詞（或代詞）"作主語時，其謂語動詞也可用復數。
neither of the texts is (are) interesting.
② 若none of后面的名詞是不可數名詞，它的謂語動詞就要用單數；若它后面的名詞是復數，它的謂語動詞用單數或復數都可以。
none of us has (have) been to america.
5、在定語從句時，關系代詞that, who, which等作主語時，其謂語動詞的數應與句中先行詞的數一致。