I saw that sentence:

" What more could anyone want? "

why the used word is 'want' and not 'wants', like with the sentence:

"Anyone wants that"

steam machwhy the used word is 'want' and not 'wants'

Only the uninflected form is allowed after an auxiliary modal verb (can want, could want, will want, would want, must want, etc.). You can never use forms like 'wants', 'wanted', or 'wanting' after those auxiliary verbs.


steam machWhat more could anyone want?
 CalifJim's reply was promoted to an answer.