What parts of speech can take the three types of interrogative clauses as comple...

Background

While studying interrogative clauses in French, I made some generalizations about the parts of speech that allow an interrogative clause to function as a complement. I found that these parts of speech can be:

• noun
• adjective
• verb

For example, in French:

• noun

Je me pose la question [si je peux payer en dollars].

• adjective

Je ne suis pas certain si je dois porter plainte.

• verb

Je sais si Marie viendra.

And interrogative clauses can be of the type

• a yes-no question
• an alternative question (this or that)
• a wh-question (who, what, where...).

To save time, the examples I have selected here are all of the yes-no question type, where "si" in French corresponds roughly to "whether" in English.

Meanwhile, in French, a declarative clause introduced by "que" (which is roughly equivalent to a declarative clause introduced by "that" in English) can serve as a complement to the following parts of speech: noun

For example:

• noun

l’hypothèse [qu’il y a de l’eau sur Mars]

• adjective

Il est tout à fait normal [que les enfants soient accueillis dès 8 heures].

• prep.

Le bureau se réunit pendant [que les délégués préparent leurs interventions].

• adverb

Le bureau se réunit alors [que les délégués ne sont pas encore arrivés].

• verb

Pierre sait [que Marie est malade].

Note that the prepositional and adverbial categories may involve parts-of-speech revisions compared to traditional grammar, resulting in structures traditionally analyzed as conjunctions being reanalyzed as "preposition/adverb + que".

By comparing the two sets, we can see that not all PoS's that accept a declarative clause introduced by "que" as a complement also accept an interrogative clause as a complement.

This discussion will carry out a parallel comparison in English. Therefore, before posing the corresponding question for English, we first need to identify which PoS's can take a declarative clause introduced by "that" as a complement. In English, a declarative clause introduced by "that" can serve as a complement to the following PoS's:

• noun

the claim [that Bill is insane]

• adjective

I am certain that Paul is dead.

• preposition

Gowda was an accidental prime minister-not even the choice of his own Janata Dal Party-and represented a departure from his predecessors [in that he came from a backward caste community, the son of poor peasant parents].

(Can a declarative clause introduced by "that" function as the complement of a preposition in English?)

• adverb

The case was so heavy that I couldn’t lift it.

(Can a declarative clause introduced by "that" function as the complement of an adverb in English?)

• verb

Olafur believes [that Björk composed Hyperballad].

My question

In English, which PoS's can take the three types of interrogative clauses as complements?

Here is a sample semantic classification of items licensing subordinate interrogatives from The Cambridge Grammar of the English Language p976.

i asking: ask, inquire, wonder, investigate

ii knowing: know, find out, remember, certain

iii guessing: guess, estimate, predict, judge

iv telling: tell, inform, point out, show

v deciding: decide, determine, make up one’s mind, agree

vi dependence: depend, have a bearing, influence, affect

vii significance: significant, important, matter, care

viii concerning: concern, about, as to, regarding

ix surprise: amaze, amazed, amazing, surprise [open type only]

x disbelief: doubt, doubtful, questionv, questionable [closed type only]

As for the subordinate interrogative's syntactic function as complement:

Interrogative content clauses (subordinate interrogatives) can be subjects or extraposed subjects, in which position they are just as much licensed by the verb (or verb + internal complements) as if they were an internal complement (following the verb).

• [Whether it would rain] was uncertain.
• It was uncertain [whether it would rain].
• [Whether it would rain] baffled the meteorologist.
• It baffled the meteorologist [whether it would rain].

But not,

• *Whether it would rain was happy.
• *Whether it would rain saw the meteorologist.

ICCs (interrogative content clauses) can be specifying predicative complements

• The main question was [whether it would rain].

ICCs can be objects or extraposed objects in complex-transitive constructions, licensed by the combination of verb + predicative complement.

• We considered [whether it would rain] unimportant.
• We considered [it] unimportant [whether it would rain].

ICCs can be an internal complement licensed by the matrix verb or a verbal idiom.

• We checked [whether it would rain].
• We didn't give a damn [whether it would rain].

ICCs can be complement of an adjective

• We weren't sure [whether if would rain].

ICCs can be complement of a noun

• We couldn't answer the question [whether it would rain].

ICCs can be a complement of a preposition. Often in this case they are an indirect complement of another word or construction, of which the prepositional phrase is a dependent. Sometimes the preposition is optional or variable.

• We were going regardless of [whether it would rain].
• There was some doubt (as to / about) [whether it would rain].
• We were uncertain (of / about) [whether it would rain].
• They couldn't agree (as to / about / on) [whether it would rain].

The above summarized with different examples from The Cambridge Grammar of the English Language, see p977-980 for a fuller discussion.