WHAT CLAUSE AND LONG NOUN PHRASE SUBJECTSUse: to introduse important information.
SINGULAR
A what-noun phrase is singular in agreement with the
verb in formal usage.A noun phrase is a group or words that express a concept and is used as a unit within a sentence.
The flu clinic had seen many cases of infectious disease.
What I want is
some milk and a cookie.
PLURAL
A what-noun phrase is plural (1) informally, if the noun
or nouns following the verb is/are plural; (2) if the relative clause noun is
plural; (3) if there are two or more what-noun
phrases.
What I want are
cookies. informal
What I want are milk and cookies. informal