to be [to-infinitive] + adjective?

[dawnngcm]

In these sentences,

I learn to be smart.
It has proved to be invaluable.

Is "to be" act as "to-infinitive" noun role? If so, it is

learn/has proved (verb) + to be [to-infinitive](noun) + smart/invaluable (adjective).

However, noun usually follow adjective but not vice versa.
e.g. good man, beautifal girl, etc.

 

[TheParser]

In these sentences,

I learn to be smart.
It has proved to be invaluable.

Is "to be" act as "to-infinitive" noun role? If so, it is

learn/has proved (verb) + to be [to-infinitive](noun) + smart/invaluable (adjective).

However, noun usually follow adjective but not vice versa.
e.g. good man, beautifal girl, etc.

***NOT A TEACHER***

Good morning.

(1) I learn to be smart. = I learn in order to be smart.
(a) Why do you learn?
(b) to be smart.
(i) infinitive phrase modifies "learn." = I learn in order (for me) to be smart. The infinitive phrase is adverbial.

(2) It has proved to be invaluable.
(a) What has it proved to be?
(i) invaluable.
(b) "to be invaluable" is an adjective here. It refers to the subject ("It").

 

[ratóncolorao]

You are pretty
She is tall
They are great/smart/intelligent....

Be is a Copulative verb. So, it is a linking verb.

 

[dawnngcm]

Thank you both!

TheParser,
Can any part of speech follow “to-infinitive”? Most examples I found are “to-infinitive” + noun, pronoun or prepositional phrase. It seems there are very rare “to-infinitive” + adjective to form a phrase.

Do you mean “to be smart” is an adverbial infinitive phrase in sentence (1) and “to be invaluable” is an adjectival infinitive phrase in sentence (2)?

It seems to me that sentence (1) and (2) are the same syntax :
verb + to-infinitive + adjective.

Then, why are they difference in grammer?

Thank you very much again!

 

[Raymott]

However, noun usually follow adjective but not vice versa.
e.g. good man, beautifal girl, etc.

You're misunderstanding or over-applying this rule.
If you have only a noun and an adjective, such as {big, man}, then yes, "big man" is right and "man big" is wrong.
But adjectives very often come later in the sentence than the noun does.
The rule you are using is only to distinguish English from many other languages which place the adjectives after the noun, as in Italian "l'uomo alto" (the tall man). It only relates to a discrete noun/adjective combination.

 

[TheParser]

Thank you both!

TheParser,
Can any part of speech follow “to-infinitive”? Most examples I found are “to-infinitive” + noun, pronoun or prepositional phrase. It seems there are very rare “to-infinitive” + adjective to form a phrase.

Do you mean “to be smart” is an adverbial infinitive phrase in sentence (1) and “to be invaluable” is an adjectival infinitive phrase in sentence (2)?

It seems to me that sentence (1) and (2) are the same syntax :
verb + to-infinitive + adjective.

Then, why are they difference in grammer?

Thank you very much again!

dawnngcm, good morning.

(1) You have asked an excellent question.

(2) I do not know enough to answer it at this moment.

(3) I have to study the matter carefully.

(4) I shall answer you as soon as I feel that I have an informed answer.

(5) Perhaps someone else will answer your question. I'm sure that s/he will do a better job than I can.

(6) Please continue to post all of your questions. This website has outstanding teachers who have many years of experience.

Have a nice day.

 

[dawnngcm]

dawnngcm, good morning.

(1) You have asked an excellent question.

(2) I do not know enough to answer it at this moment.

(3) I have to study the matter carefully.

(4) I shall answer you as soon as I feel that I have an informed answer.

(5) Perhaps someone else will answer your question. I'm sure that s/he will do a better job than I can.

(6) Please continue to post all of your questions. This website has outstanding teachers who have many years of experience.

Have a nice day.

Good day to you.

You did great help actually! So, many thanks!

You gave me hint for key word searching "adverbial infinitive phrase" in internet. I found some of them solve my other grammatical problems. Before that, I used key word searching "verb + to be + adj" and "to be + adj" but I hardly found anything help.

 

[TheParser]

***NOT A TEACHER***

dawnngcm, good morning.

(1) I am disappointed that no one else has yet answered all of your questions.

(2) May I make a respectful suggestion: if you submit a short post with only one question, maybe more people will reply.

(3) I searched all my books and checked out the Web. I am NOT satisfied with my findings, but here is what I learned.

(4) You say that the combination "verb + to-infinitive + adjective" is "rare."

(5) I had never thought about that matter before. You may be right when it comes to adverbial phrases of purpose ending in an adjective.

(6) I found only one -- in my favorite grammar book: He struggled TO GET FREE. The book says it expresses "mental direction" or "purpose."

(7) It is similar to your "I learn to be smart" or "I study (in order) to become smart." I feel that is an adverbial phrase: it explains your purpose for studying.

(8) But remember, please: adverbial infinitive phrases are very common -- but NOT those that end in an adjective. I couldn't find any other examples!!! Of course, they must exist.

(9) When it comes to adjectival phrases, however, there many many examples. In other words, they are far from being "rare."

(10) The news proved/turned out to be true./He lived to be old./The weather continues to be pleasant./He seems to be all right./ The children appear to be asleep./ His ambition is to become rich.

(11) They seem to often appear in passive sentences: He is said to be good./ He was believed to be rich./ He is said to be quiet./The traffic was reported to be heavy./Her father was presumed dead.

(12) You asked how the combination "verb + to-infinitive + adjective" can sometimes be adverbial and sometimes adjectival. I have no answer. Perhaps you can submit a similar question in another post.

Good luck. I'm sure you will soon be speaking English very well.

 

[Raymott]

(10) The news proved/turned out to be true./He lived to be old./The weather continues to be pleasant./He seems to be all right./ The children appear to be asleep./ His ambition is to become rich.

This construction as adverbial is not rare.
Here are some pairs; the first is TheParser's, the second contains an adverbial:
He lived to be old; He lived to be pampered. (Why did he live?)
The weather continues to be pleasant; She smiles to be pleasant.
The children appear to be asleep. Whenever there is work to be done, the children appear, to be useful.
Also:
He appeared to be alright; He appeared to alright to be let out of hospital. (in order that he be let out of hospital).

 

[dawnngcm]

He lived to be old; He lived to be pampered. (Why did he live?)
The weather continues to be pleasant; She smiles to be pleasant.
The children appear to be asleep. Whenever there is work to be done, the children appear, to be useful.
Also:
He appeared to be alright; He appeared to alright to be let out of hospital. (in order that he be let out of hospital).

Thanks TheParser and Raymott.

Your examples provide in this single thread are much more than I’d found in last week!


Raymott,
I think and re-think the above examples. At first, I’ll ask “what” (He lived to be old)in the question rather than “why” (Why did he live?). Yet, I think they can be“Why” questions.