文档介绍：引导宾语从句陈述句::if/whether“是否”) Idon'tknowif(wheather):特殊疑问词Idon’:omorrow,:Heisn’tcomingbecauseheisbusy. Sinceitisraining,wewon’’tready,----:::Thoughheisachild,:'esback. (主句为一般将来时,从句则用一般现在时)'tmeteachothersincesheleftherelastyear.(主句为现在完成时,从句用一般过去时) MyfathercameinwhileIwasdoingmyhomework.(从句常用进行时态)用法表因果for Heisabsenttoday, Hehurthisleg,sohecouldn',while表示对比、转折。Somepeoplelovecats,whileothershatethem.---etodinnertonight?---I'dliketo,butI'…but…意思为"不是……而是……":although…yet…,但although不与but连用。Althoughhewasweak,buthetriedhisbesttodothework..(╳)(对)Althoughhe Althoughhewasweak, yethetriedhisbesttodothework(√) Althoughhewasweak,buthetriedhisbesttodothework..(╳)Althoughhewasweak,yethetriedhisbesttodothework(√)并列连词表选择orShallwewalkortakeabus?Takethisbus,oryoucan’…