A. She is likely/sure/certain to start her new project.

She may start her new project.

Are the senses and the roles of the to inf. the same as 'start her new project' of 'may', complementing the (modal) verbs and indicating the action of the subject? Do we speak them in the same sense? If we classify the main verb of modal verbs ad the complement of the modal verbs, do we also classify the inf. above as the complements of the 'be + adj.'s? Or is the to-inf. just an object?

B. I'm dying/willing/curious/anxious/eager to eat that cake.

I'm dying/willing/curious/anxious/eager for that cake.

Do we speak the to inf.s above in the same sense as the 'for~'s? Do they mean the same, expressing the subject's wish, desire, or plan as adverbials?

C. I hoped for some money./I hoped to take the train.

I begged for more candy./I begged to go to the movies.

I longed for an A./I long to get an A.

I volunteered for the job./I volunteered to help the kids.

I was aiming for the trophy./I was aiming to receive the trophy.

Do these to inf. express desire/intention as adverbials, same as the 'for+N's? Or, are they just objects?

  • 2
    Sure, likely, and certain are also modal predicates (though not modal auxiliary verbs), because they express modal semantics, in this case Epistemic modality. Long (v), volunteer, beg, hope, and aim express Deontic modality. In each case, the infinitive clause is a complement of the predicate, usually with to. Though it's not an adverbial -- it's usually a noun phrase object when it's a verbal complement. Commented Sep 7, 2020 at 22:08
  • Thank you, sir. Then, how about the one at Question B? And do Americans really think the to-infinitives after likely/sure/certain and hope/.../aim as noun phrases? Commented Sep 8, 2020 at 20:31
  • Any verb that means want, in one mode or another, really means want to have; and when we use a noun phrase (instead of a clause) as object for these verbs, they all mean want (or whatever) to have that noun phrase. So dying, willing, curious, anxious, and eager can take NP object with for, too. Commented Sep 8, 2020 at 21:05
  • Forgive me, sir. I've been trying to diagnose such to-infinitives but couldn't. I guess I have to ask you questions some more. Commented Sep 9, 2020 at 1:44
  • appear/seem/prove/happen/chance/turn out/have + to inf. Commented Sep 9, 2020 at 1:45

2 Answers 2


Though you're correct that many of the pairs you've provided are similar semantically, you've confused the functions complement, object, and adjunct(traditional grammar's 'adverbial').

First off, you'll want to get form and function separated. The form of dependent clauses, and phrases, is determined by their internal structure: NPs are headed by nouns and allow a certain range of dependents; to-infinitival clauses are headed by a verb in plain form and allow a range of dependents different from those found in an NP. So, a to-infinitival clause will never be an NP, but it may appear in the same functional category in a larger structure.

Then, you can start to look at the function of these dependent clauses and phrases in clause or phrase structure.


She - is - likely [to - start - her new project]

Subject - predicator - predicative complement



She - may - [start - her new project]

Subject - predicator - catenative complement

In I, to start her new project is a to-infinitival clause functioning as dependent (specifically a complement) in the adjective phrase headed by likely. It is a complement because it is allowed only by likely and other adjectives allowing a to-infinitival clause as complement, not by adjectives in general: *dry to start her new project.

In II, start her new project is a plain infinitival clause functioning as direct dependent (specifically a complement) of the predicator may. The specific type of complement is a catenative complement. These are non-finite (plain infinitival, to-infinitival, gerund-participial, or past participial) clauses specifically allowed by the verb acting as predicator.

It is necessary to note here that the to-infinitivals in your examples are not adjuncts, but in fact complements in AdjPs in A and B, and catenative complements in C. This becomes clear when we note that in order may not be inserted while keeping the same meaning,

?I'm willing in order to eat that cake. (Willing to do what?)

I'm dying in order to eat that cake. (How terrible!)


*I hoped in order to go to the movies.

I begged in order to go to the movies. (What did you beg for/to do?)

*I long in order to get an A.

I volunteered in order to help the kids. (What did you volunteer for/as/to do?)

I was aiming in order to receive the trophy. (What were you aiming at/to do?)

Though there is some overlap between verbs that allow different sorts of complement - object, catenative complement, predicative complement - the complements themselves are best viewed as distinct categories each allowed by a specific set of verbs. For example, what follows get in the each of the sentences below is a distinct sort of complement:

Mark - got - a dog [object]

Mark - got - excited to go one the trip. [predicative complement]

Mark - got - me - a dog [indirect object - direct object]

Mark - got - chosen as goalie [catenative complement(past participial clause)]

Mark - got - to go first [catenative complement(to-infinitival clause)]

Mark - got - me - to go first [object - catenative complement(to-infinitival clause)]

Though get allows these constructions, if we pick another verb that allows the first, say sniff, we'll quickly see that the others are not allowed.

Mark - sniffed - a dog [object]

*Mark - sniffed - excited to go on the trip. [predicative complement]

*Mark - sniffed - me - a dog [indirect object - direct object]

*Mark - sniffed - chosen as goalie [catenative complement(past participial clause)]

*Mark - sniffed - to go first [catenative complement(to-infinitival clause)]

*Mark - sniffed - me - to go first [object - catenative complement(to-infinitival clause)]

Though the last two could be understood as adjunct of purpose in some strange context, they are not understood in a sense similar to the catenative complement examples with get.

Long story short, yes all of the pairs you provided have similar meanings, no their structures cannot be analyzed as equivalent.


hope/willingness/reluctance/anxiety/attempt + to-V

I see that this to-V is a noun complement, since the nouns' adj./v. forms take their noun complements. But...

  1. opportunity/chance(s)/possibility/capacity/power + for N/to-V

    Is the to-V of opportunity/../power an adjective clause that tells us what the nouns are for?

  2. 'effort' + to-V/for N

    Is the to-V of 'effort' an adjective clause that tells us the intention of the agent of 'effort'?

  3. tendency+ to-V (which is the verbal complement of 'tend')

    Is the to-V of 'tendency' not a noun phrase but just a verbal complement?

  4. obligation/duty/responsibility + to-V

    Is the to-V of obligation/duty/responsibility an adjective phrase that shows the fixed necessity of the agent's action?

My diagnoses of 1., 2., and 4. are on the ground that there are the usages of to infinitives as adjective phrases or adverbials that show the meanings but in just a slightly different way.

Sorry for bothering you so much, sir, but I'm having a hard time studying and diagnosing these to-Vs. There are no textbooks for learners' giving the information. (well, at least of the ones in South Korea.) I'm very thankful for your help.

  • 2
    You should not limit yourself to textbooks. Study the literature; read answers here. Learn how to think and talk about English syntax before you attempt to build your own version. NP complement clauses are usually related to verbal complements, and have the same range of semantic uses; (1) and (4) are modal -- (1) is epistemic, and (4) is deontic -- while (2) and (3) are essentially aspects. Complement clauses look like noun phrases from above, and clauses from below; they are actually both. Depends on where you're metaphorically standing. And this is irregular behavior. Let's stop here. Commented Sep 12, 2020 at 13:34
  • 1
    @John Lawler 'they are actually both'. "Let's stop here" looks hopeful. Commented Sep 14, 2020 at 11:33

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.