I start with a simple sentence:
“I climb the ladder.”
This contains a nice transitive verb with a clear direct object. If I slightly modify the sentence:
“I climb up the ladder.”
I believe that I have not changed the essential nature of the sentence ( climb is still transitive); I have only added an adverb indicating the direct of the climb. A friend believes that the new sentence is fundamentally different. She believes that climb is now intransitive and that up the ladder is a prepositional phrase!
Which of us is correct?