I am working through sentence diagrams and continue to have trouble determining when a construction is an infinitive verbal or if it is simply a prepositional phrase.
"Stephanie likes to fix cars"
As per my book, the answer is that "to fix cars" is an infinitive verbal.
"The stain, the sticky spot, needs to be cleared"
As per my book, the answer is that "to be cleared" is simply a preposition.
Any guidance will be much appreciated!