1)名词性从句及不定式、动名词作主语时，谓语动词一般用单数形式。
Tofinishtheworkinadvanceiswhathewants.
Smokingcigarettesisdangeroustoyourhealth
Whatseemseasyintheoryisdifficultinpractice.
Whatcausedtheaccidentisacompletemystery.
但是，what引导名词从句作主语时，其表语是复数形式时，系动词也可以是复数形式。
Whatwebadlyneedherearequalifiedteachers.
2)当主语是单数，后面跟着由including,with,togetherwith,alongwith,like,inadditionto,aswellas,ratherthan,but,except,morethan,accompaniedby等连接的短语时，谓语动词用单数。
Maryaswellashersisterlikeslisteningtomusic.
DoctorRichards,togetherwithhiswifeandthreechildren,istoarriveontheafternoonflight.
Mybestfriendratherthananyoneelsehasgotthefirstprizeinthespeechcontest.
3)one,oneof,every,everyone,everybody,each,manya,either,neither,noone,nobody,anyone,anybody,someone,somebody用作主语或修饰主语时，谓语动词用单数形式。
Eachman,womanandchildhasthesameright.
Manyastudentdoesn'tliketodotheirhomework.(manyastudent＝manystudents)
Eitherofstudentsisgoingtocompeteforthepresidentofthestudents'union.Morethanonepersonwasinvolvedinthecase.
Neitheroftheyoungmenwhohadappliedforapositionintheuniversity____.A)hasbeenaccepted
neither用作主语或修饰主语时，谓语动词用单数形式。此外，定语从句用过去完成时，主句应用一般过去时，故答案为C。
4)and所连接的两个单数名词作主语，指同一人、同一件事或同一概念时，其谓语动词用单数。例如：Mybestfriendandadviserhaschangedhismindagain.
Bread,butterandeggsistypicalAmericanBreakfast.
5)表示时间、距离、重量、体积、金钱的复数名词，作主语时作为整体来看待，谓语动词通常用单数。
Fivethousandsdollarsisquitealargesumofmoneytome.
Fiftymilesistoolongadistanceforonetowalkonfoot.
Tenyearshaspassedbuthedidn'tchangeatall.
6)"aportionof,aseriesof,akindof,abodyof,aspeciesof,apairof+名词"作主语时，其谓语动词一般用单数形式。
AseriesofaccidentshasoccurredrecentlyinAmerica.
Apairofnewglassesisquiteexpensive.
7)事件、机构、国名、作品等专有名词作主语时，谓语动词用单数。
TheAdventuresofHuckleberryFinnwaswrittenbyMarkTwainanditisaninterestingbook.TheUnitedNationsisanorganizationtodefendworldpeace.
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