Grammatical structure of "The one thing we know how to measure best is IQ."

Question

The one thing we know how to measure best is IQ.

I was not able to understand this sentence's grammatical structure.

I think, in this sentence, the noun clause is "the one thing we know how to measure best". Here, I have a question about the three elements, "the one thing", "we know", and "how to measure best". How are they connected with each other?

I am not sure the reason why it is okay that "how to measure best" can come after "we know".

Could someone please give me a lecture?

Answer 1

In English, a relative clause usually has a gap corresponding to the noun phrase that it's modifying. To understand the structure of a relative clause, we find this gap. For example, in "the man whom I saw", the gap is the direct object of saw: "the man_i whom_i I saw ____i"; the relative clause "whom I saw" corresponds to a regular declarative sentence like "I saw him".

In your example, "the one thing we know how to measure best", the gap is the direct object of measure: "the one thing_i Ø_i we know how to measure ____i best"; the relative clause "Ø we know how to measure best" corresponds to a regular declarative sentence like "We know how to measure it best".

---

Incidentally, you write:

I think, in this sentence, the noun clause is "the one thing we know how to measure best".

As it happens, that is not a noun clause; it's a noun phrase, headed by the noun "thing". It contains a clause, but that's not the same thing as being one!

Answer 2

OK, a lecture, as requested.

First, it is necessary to repeat that the sentence in the example is egregiously false; in fact, it's a damned lie, derived from another lie. "IQ" is nonsense, doesn't exist, and can't be measured.

So I'm going to substitute a true sentence with the same structure, to avoid spreading noxious nonsense. Instead of measuring, we'll bake, and instead of "IQ", we'll bake pies. On Pi Day, that seems reasonable (sorry; I am informed that Pi day was yesterday, but I doubt it matters to the pies).

• [The one thing we know how to bake best] [is pie].

Second, the grammatical structure of the sentence is that it's a complex sentence, like most English sentences, with [a long complex relative clause as the subject], is as the main verb, and the auxiliary verb, for the predicate noun pie, forming a verb phrase [is pie].

But things have been done to this sentence, and I'll take them apart. I'll put back in the relative pronoun that, taken out because it's not the subject, but rather the object, of bake (best):

• The one thing [(that) we know how to bake best] is pie.

The one thing is a noun phrase modified, defined, and restricted by the [relative clause]. It's there to show the one (uniqueness); otherwise it means the same as the contracted relative what (= the thing which), so this reduces to

• What we know how to bake best is pie.
  (Note that best includes the uniqueness of one, so no problem leaving out one.)

And this sentence is a construction called a Wh-Cleft, which is derived by adding a dummy be (here it comes out as is, which is pretty common) in order to separate into two the topical parts of the sentence from an original, simpler statement:

• We know how to bake pie best.

in order to emphasize one part of the sentence (the part after the be in a Wh-cleft); the rest of the sentence goes before the be and is presupposed to be true. I.e, a Wh-cleft

• What we know how to bake is pies.

presupposes that we know how to bake some thing, and asserts that that thing is pies. If you negate the sentence, you can negate pies, but you can't deny our baking knowledge.

• What we know how to bake is not pies.

This is one variety of Cleft sentences in English. There are others.

Answer 3

(1) The one thing we know how to measure best is IQ.

You were "not able to understand this sentence's grammatical structure" because one thing comes before not just how to measure best but even we know, when one thing is semantically related to measure. That is, in (1), one thing and measure are too far away from each other for you to understand.

The same level of difficulty is not seen in (2), although one thing still comes before measure, unlike the normal order of measure one thing:

(2) The one thing we can measure best is IQ.

Therefore, you're having difficulty understanding sentence (1) due to the distance between, as well as the switched order of, measure and one thing.

Neither the distance nor the switched order, however, plagues competent native speakers of English. The distance can be even greater as in (3), and still poses no problem for them:

(3) The one thing we know they learned how to measure best is IQ.

Sentence (2), whose grammatical structure is the simplest of all, can be easily understood by simply comparing it with (2'), where measure and one thing stand side by side and in the normal order:

(2') We can measure one thing best, and it's IQ.

Similarly, sentences (1) and (3), whose grammatical structures are more complex, can also be understood by comparing them with (1') and (3'), respectively:

(1') We know how to measure one thing best, and it's IQ.

(3') We know they learned how to measure one thing best, and it's IQ.

Answer 4

There is no relative phrase in prenuclear position, so gap is related directly to the nominal “one thing”.

Answer 5

The one thing . . .[that] .....we . .know .how to measure best

The one thing . . .{that ......we . .know [how to measure best]}

Det quan. noun ..{rel. .. .. subj ..verb ..[adv. .. ..Inf. .. adv.]}

Det quan. noun ..{rel. .. .. subj..verb .. [. ..complement .. .]}

Det quan. noun ..{.. .. .. .. .. .. .. relative clause.. .. .. .. .. .. .. }

{.. .. .. .. .. .... .. .. .. .. .. .. .NP.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..}