What we have here is admittedly a tough grammar issue to crack, so it’s best to keep an open mind about it until the grammar elements involved are fully clarified and their relationships to one another fully understood.
Let me begin by saying that not all base verbs preceded by “to” are infinitives.
By definition, an infinitive is a verb form normally identical in English with the first person singular that performs some functions of a noun and at the same time displays some characteristics of a verb and that is used with
to (as in “I asked him
to go”) except with auxiliary and various other verbs (as in “no one saw him
leave”). (Definition by
Merriam-Webster’s 11th Collegiate Dictionary)
The verb forms in the following sentences are infinitives or infinitive phrases based on that definition:
1. “
To forgive is divine.” (The infinitive “to forgive” is the subject)
2. “She hated
to play the violin.” (The infinitive phrase “to play the violin” is the direct object)
3. “I find it delightful
to play the violin.” (The infinitive phrase “to play the violin” is an adverbial modifier)
In contrast, the “to + base verb + modifier” forms in the following sentences are prepositional phrases:
1. “She is pleased
to play the violin.” (The prepositional phrase “to play the violin” is an adverbial modifier of the adjective “pleased”)
2. “She went
to see the school principal.” (The prepositional phrase “to play the violin” is an adverbial modifier of the verb “went”)
Now, regarding this statement of yours: “About it, you also argue that ‘pleased’ isn’t an adjective but an intransitive verb. In grammar, do we really have intransitive verbs in passive forms?”
Yes, the word “pleased” is an intransitive verb in the passive form in the following sentence: “I’m
pleased to talk to you.” This is because the subject of the sentence is the receiver of the action of the verb, not its doer. The verb “please” would be transitive in the following active-voice sentence where the subject, the infinitive phrase “to talk to you,” is the doer of the action: “To talk to you
pleases me.” It is also transitive in the active-voice sentence “She
pleases me greatly,” where the subject is the pronoun “she.”
Regarding this observation of yours: “Second, I observe that in the sentence ‘It’s nice to talk to you,’ you’ve given as a legitimate example of constructions having infinitives next to adjectives, itself not qualifying to be so. To my mind, it’s a sentence that uses an infinitive phrase as an appositive of the pronoun ‘it.’ Here is how I would change the position of the infinitive phrase without wrecking the original meaning of the construction: ‘It, to talk to you, is nice,’' which has the appositive interrupting the flow of the sentence and ‘To talk to you is nice,’ which do away with the pronoun ‘it.’”
I’m afraid that in the sentence “It’s nice to talk to you,” it’s grammatically incorrect to think of the word “it” as the appositive of the phrase “to talk to you,” which you consider an infinitive phrase or a noun form—which it actually isn’t. In that construction, “it” is actually an
expletive, which functions as an anticipatory or dummy subject—a grammatical device—that shifts emphasis to a part of the statement other than the subject; the expletive is not to be taken as a pronoun because it has no antecedent noun and actually has little or no meaning by itself. (Click
this link to About.com for a concise explanation of the expletives ‘it’ and ‘there.’) This being the case, it doesn’t serve as an appositive of anything in that sentence (Click to
“How appositives can give life and texture to writing” in the Forum). As to the phrase “to talk to you,” based on the clarifications I made earlier, it’s not an infinitive phrase but a prepositional phrase of the form “preposition (‘to’) + verb (‘talk’) + preposition (‘to’) + object of the preposition (‘you’), functioning as an adverbial modifier of the adjective “nice.”
Finally, in the sentence “He was hesitant
to allow his child going swimming,” the phrase “to allow his child going swimming” is definitely not an infinitive phrase but a prepositional phrase functioning as adverbial modifier of the adjective “hesitant.” Observe that the phrase in question doesn’t function as a direct object of the verb “hesitant”; if it did, that would have been telltale proof that it is an infinitive phrase. What we have here is a prepositional phrase of the form “preposition (‘to’) + base form of the verb (‘allow’) + direct object (“his child’) + gerund phrase as noun complement (‘going swimming’).”
I hope this further explanation has thrown more light into the discussion.