[Mohammed Abu Risha]

Here is my suggestion:
Harry saw the people with a telescope

Harry= Subject (Noun Phrase)
Saw= verb
The people = Object (Noun Phrase)
With a telescope = Adverbial (prepositional Phrase)


Object: The people (noun Phrase)
The= Determiner
People = Head Noun

Adverbial: With a telescope (prepositional Phrase)
With = Preposition
A telescope = Noun Phrase
A= Determiner ,,,,,, telescope = Head Noun