You know about the simple sentence (subject and predicate). Now we will add another element, a direct object (marked in blue).
The man wrote a letter.
The man (subject/noun) wrote (predicate/verb) a letter (direct object/noun).
The letter is the receiver of the action and answers the question “What?”
(What did the man write?)
Now we can add an indirect object (marked in red), which will answer the question “To whom?” or “For whom?”
Here are some other examples of direct objects (in blue) and indirect objects (in red).
The man wrote his girlfriend a letter.
He gave his guests the tour.
He bought his love a ring.
She paid him ten dollars.
Sometimes we want to say the same thing in a different way. By using a prepositional phrase (a group of words beginning with a preposition) we can substitute it for the indirect object by putting the phrase after the direct object. The prepositional phrase is marked in green.
“The man wrote his girlfriend a letter” becomes “The man wrote a letter to his girlfriend.”
“She paid him ten dollars” becomes “She paid ten dollars to him.”
“He bought his love a ring” becomes “He bought a ring for his love.”
You can recognize a prepositional phrase by the prepositions at the beginning.
Some prepositions are:
To, for, with, after, without, in, by, beside, among, when, at, over, beyond, through (and many others).
So there you are — direct objects, indirect objects, and prepositional phrases. You can add these to your list of “parts of speech.”