what引导的从句的谓语的单复数怎么决定？

elites

what引导的从句，而且what在从句里作主语的时候，我一直以为谓语全用单数，不过做大全885sectionb的第10提，what are called tiles，就用的复数的谓语。是不是因为能通过tiles推出主语是复数才用的复数谓语，一般情况下还是用单数？

himba

What 引导的名词性从句做主语－主句谓语动词由 be 动词后的名词决定。What 在句中做主语：What is… is…. / What are … are… e.g. What is difficult to understand is A.；What are difficult to understand are A and B.What 在句中做宾语：What I want is A.；What I want are A and B.e.g. What I want is your happiness.；What I want are good job and happy life.