Grammar notes

Parts of sentences:
Subject: who or what does the action
Predicate: the action

^ Those two are the essentials

Direct object
Subject complement
Indirect object - Not that common
Prepositional Phrase

Horace (Subject) wrote (Predicate) a letter (direct object) to Priscilla (P.P)
Horace (Subject) wrote (Predicate) Priscilla a letter

If you place the prepositional phrase before the direct object, it will become an indirect object.
An indirect object will always come before the direct object

A prepositional phrase always begins with a preposition and ends with a noun.

Intransitive verbs: verbs that can't have an object

Javier (Subject) works (predicate) at the bookstore (Prepositional phrase) and makes (predicate) very little money (direct object).

You can't have an indirect object when you don't have a direct object.

If she (Subject) likes (Predicate) the car (Direct Object), she (Subject) will buy (Predicate) it (Direct Object). <= Modal verb