I saw her play the piano. OK
I saw her TO play the piano. NOT OK
I want you play the piano. NOT OK
I want you TO play the piano. OK
I've been trying to reseach and figure this out. My grammar sense tingles when I hear the wrong ones so I FEEL they are wrong but for the life of me I don't know WHY they are wrong.
indirect object? prepositional phrases? I tried using an online sentence parser
http://beta.visl.sdu.dk/visl/en/parsing/automatic/trees.phpThat thing tells me "to play the piano" and "play the piano" are adverbial clauses which makes no sense to me so I think is wrong.
Any ideas? Any help would be appreciated.