what与that用作连接词引导从句的区别

当what用作连接代词，引导名词性从句时，可引导主语从句、表语从句和宾语从句（不可引导同位语从句）；它本身在句中充当主语、宾语或表语。[解题过程]注意what和that引导名词性从句的差别：一、当what用作连接代词，引导名词性从句时，可引导主语从句、表语从句和宾语从句（不可引导同位语从句）；它本身在句中充当主语、宾语或表语。1、what表示“所以……的（事）”的意思，相当于“thething(s)that……”、“allthat……”、“thatwhich……”、“everythingthat……”等。例如：（1）LeaveitwithmeandI’llseewhatIcando.(what引导宾语从句，并作do的宾语。)（2）Whatyouhavedonemightdoharmtootherpeople.(what引导主语从句，并在从句中作宾语。)（3）Whathesaidatthemeetingastonishedeverybodypresent.(what引导主语从句，并在从句中作宾语。)（4）Whatismostimportantinlifeisn’tmoney.(what引导主语从句，并在从句中作主语。)（5）Butwaittillyouseewhatwe’llmakeforyoutoyourownmeasure.(what引导宾语从句，并在从句中作宾语。)（6）Whathewantedtoseewasanendtoallthearmiesoftheworld.(what引导主语从句，并在从句中作宾语。)2、what表示“所……的（人）”的意思，相当于“thepersonthat……”等。例如：（1）Heisnotwhatheusedtobe.(what引导表语从句，并在从句中作表语。)（2）Sheisnolongerwhatshewasfiveyearsago.(what引导表语从句，并在从句中作表语。)二、that当that用作连接词，引导名词性从句时，可引导主语从句、表语从句、宾语从句和同位语从句，that在从句中既不充当任何成分，也无实际意义，仅起着连接句子的作用。和般不可省略（宾语从句除外）。若从句置于句子后面，代词it作形式主语。例如：（1）Itworriedherabitthatherhairwasturninggrey.(that引导主语从句)。（2）ItisafactthatChineseisacceptedasaninternationallanguage.(that引导主语从句)（3）Canyoubelieve(that)insucharichcountrythereshouldbesomanypoorpeople?(that引导宾语从句)（4）Tomfeltthathekneweverybody’sbusinessbetterthantheyknewitthemselves.(that引导宾语从句)（5）Weheardthenewsthatourteamhadwon..(that引导同位语从句)（6）Anotherproblemisthatgoodsoilisgraduallylost.(that引导表语从句)（7）Butthetruthisthateveryoneshouldtakecareofdisabledpeople,notjustthegovernment.(that引导表语从句)