主句如果是一般现在时态从句可以是任何时态如:1,ithinkheisstudyingEnglish.2,ithinkhehasfinshedEnglishhomework.3,ithinkheisgoingtostudyEnglishtomorrow.4,payattentiontowhattheteachersaid.主句如果是过去时态那么从句应该是表示过去的某种时态(过去时,过去进行时,过去将来时,过去完成时).如.hesaidtherewerenoclassesyesterdayafternoon.2.hesaidthathewasgoingtotakecareofthebaby.3,theteacheraskedmeificouldfinishthetaskontime.4,hesaidthathehadgonehongkong.如果主句是过去时态而从句式叙述某一客观真理和事实时从句用一般现在时.如,hesaidthatherfatheristwenty-eigntyearsolderthanhis.