Recall that in English, a verb may be transitive, intransitive, or linking. It is transitive when it’s an action verb that absolutely needs a direct object to make sense in a sentence (like the verb “caught” in “The police caught a thief”), intransitive when it’s an action verb that doesn’t need and can’t take a direct object at all (like the verb “sneezed” in “She sneezed”), and linking when it’s a verb that doesn’t express action but simply connects the verb to the predicate (like the verb “is” in “The day is hot”). By definition, of course, a direct object is a noun or pronoun that receives the action of a transitive verb or shows the result of its action, as the noun “thief” in the first sentence I gave as example above.
Many verbs, of course, can either be transitive or intransitive depending on how they are used in the sentence. For example, “breaks” is transitive in “She often breaks the rule” because it needs the direct object “rule” for the sentence to make sense. On the other hand, “breaks” is intransitive in “When dropped on a hard surface, glass breaks” because it needs no direct object for the sentence to make sense.
Now, in the case of the two verbs you presented, “yearn” and “proceed,” they are indeed both intransitive verbs and as such shouldn’t be able to take a direct object at all. Why then, you ask, do these verbs each appear to take an object in the sentence “I yearned to go there” and “He proceeded to deny the truth”?
The answer—and mark this very carefully—is that although intransitive verbs can’t link up with a direct object, they can indirectly do so by using a preposition as grammatical intermediary. The noun, pronoun, or noun phrase linked to the verb in this manner is called the object of the preposition. In the sentence “She sneezed on her hankie,” for instance, the intransitive verb “sneezed” is linked by the preposition “on” to “her hankie” as object of the preposition. In effect, it is the preposition that “receives” the action of the intransitive verb “sneezed” and then transmits that action to “her hankie” as object.
The same thing applies to the two sentences you presented. In “I yearned to go there,” the intransitive “yearned” is linked by “to” to the words “got there,” and the whole phrase “to go there” actually serves as the direct object of the verb “yearned.” In “He proceeded to tell the truth,” the intransitive “proceeded” is linked by “to” to the words “tell the truth,” and the whole phrase “to deny the truth” serves as the direct object of the verb “proceeded.” Keep in mind that in these two sentences, “to go there” and “to deny the truth” are both infinitive phrases—noun forms—that function as a direct object.
By this time the answer to your second question should be obvious. In “He complains about everything,” the direct object of “complains” is the whole noun phrase “about everything,” where “everything” is the object of the preposition “about.”
