{"slug":"pro-form-a-taxonomy","title":"Pro-form | A taxonomy","date":"2026-03-06T08:06:29.947Z","excerpt":"","tags":["language","taxonomy"],"order":44,"published":true,"content":"

In the study of English grammar, pro-forms are categorized according to three primary criteria: the grammatical category they substitute for (noun phrase, verb phrase, adjective, adverb, or clause), the type of reference they establish (anaphoric — referring back, cataphoric — referring forward, or deictic — pointing to the context of utterance), and their semantic content (whether they carry inherent meaning or derive their meaning entirely from their antecedent). As a single pro-form may operate across multiple categories simultaneously — so can substitute for a verb phrase (she said so), serve as a pro-clause (if so, the hypothesis fails), or function as a degree pro-form (she is so brilliant) — these classifications are best understood as overlapping systems rather than mutually exclusive categories.

Pro-forms are the substitution words of English. Where full lexical expressions name, describe, and specify, pro-forms stand in for them — reducing repetition, enabling cohesion, and allowing discourse to move efficiently by pointing rather than repeating. Pronouns are the most familiar pro-forms and received their own dedicated article in this series, but they are only one subclass of a broader substitution system that extends across all the major grammatical categories. English has pro-forms for noun phrases, verb phrases, adjective phrases, adverb phrases, and entire clauses. Understanding the full system reveals the extraordinary economy and coherence of English reference management.

1. Pro-Nominals (Noun Phrase Substitutes)

Pro-nominals substitute for noun phrases. Pronouns — covered in full in the dedicated pronoun article — are the primary pro-nominals, but the category extends beyond the traditional pronoun paradigm.

A. Personal, Demonstrative, Interrogative, and Indefinite Pronouns

The full pronoun system (I, you, he, she, it, we, they; this, that, these, those; who, what, which; someone, nobody, everything, etc.) constitutes the core of the pro-nominal system and is analyzed in detail in the pronoun taxonomy.

B. One as a Pro-Nominal

The pro-form one (and its plural ones) substitutes for a count noun phrase, preserving the head noun but allowing the determiner and modifiers to change. It is distinct from the personal pronoun one (discussed in the pronoun article) and from the numeral one.

She preferred the second methodology to the first one. (one substitutes for methodology)
The recent findings are more reliable than the earlier ones. (ones substitutes for findings)
She used a glass microscope slide rather than a plastic one. (one substitutes for microscope slide)

One/ones can only substitute for count nouns — not mass nouns and not proper nouns:

?She preferred the second data to the first one. ✗ (data is mass)
She drank the red wine rather than the white one. ✓ (wine as count noun — a glass/variety of wine)

One retains the head noun's meaning but allows the modifiers around it to vary — in she preferred the second methodology to the first one, the full form would be the first methodology, but one substitutes for methodology while the determiner the and the ordinal first are new.

C. Do So, Do It, Do That as Pro-Verbal Nominals

In certain constructions, do so, do it, and do that function as nominal substitutes for an action or event just described:

She completed the analysis, and he did so as well. (did so = completed the analysis)
She was asked to revise the methodology, and she did it reluctantly. (did it = revised the methodology)
He predicted the outcome correctly. I knew he would do that. (do that = predict correctly)

These forms blur the boundary between pro-nominal and pro-verbal substitution.

2. Pro-Verbals (Verb Phrase Substitutes)

Pro-verbals substitute for verb phrases — the predicate of a clause — allowing the speaker to refer back to an action or state without repeating the full verbal expression.

A. Do as Pro-Verbal

The primary pro-verbal in English is the auxiliary do, which substitutes for a full verb phrase in elliptical constructions. It carries the tense and agreement of the original verb phrase but replaces all of its lexical content.

She analyzes data more carefully than he does. (does = analyzes data)
They published more papers last year than they did the year before. (did = published papers)
She completed the experiment, and so did he. (did = completed the experiment)
I don't believe the hypothesis, but she does. (does = believes the hypothesis)

Do as pro-verbal is one of the most productive mechanisms of ellipsis in English. It allows two clauses to be compared, contrasted, or coordinated without repeating the full verb phrase — and the comparison itself becomes the communicative focus.

Do-support in questions and negatives:

The same do that serves as a pro-verbal also provides the structural support for questions and negations of lexical verbs (do you understand?, she does not agree). These are formally related phenomena — in both cases do is carrying grammatical information (tense, agreement, polarity) that the lexical verb would otherwise carry.

B. So and Not as Pro-Clausal Substitutes after Verbs of Saying and Thinking

After a restricted set of verbs — say, think, believe, expect, hope, suppose, fear, imagine — the forms so and not function as substitutes for an entire clause:

So substitutes for a positive clause:

\"Will the replication succeed?\" \"I think so.\" (so = that the replication will succeed)
She said so. (so = whatever was under discussion — the positive proposition)
I hope so. (so = that the desired outcome will occur)
It appears so. (so = that the stated proposition is true)

Not substitutes for a negative clause:

\"Will the replication succeed?\" \"I think not.\" (not = that the replication will not succeed)
I hope not. (not = that the undesired outcome will not occur)
I'm afraid not. (not = negative of the proposition under discussion)

The verbs that license so and not substitution are those expressing propositional attitudes — the speaker's stance toward the truth of a proposition. I think so means I think that [the proposition under discussion] is true; I hope so means I hope that [the proposition] will be true.

C. Auxiliary Pro-Verbals in Tag Questions and Short Answers

The English tag question system uses auxiliary verbs as pro-verbals, substituting for the full verb phrase of the main clause while reversing its polarity:

She conducted the experiment, didn't she? (didn't substitutes for conducted the experiment, negated)
They haven't published yet, have they? (have substitutes for haven't published yet, affirmed)
He will submit by Friday, won't he? (won't substitutes for will submit by Friday, negated)

Short answers operate on the same principle:

\"Did she complete the analysis?\" \"Yes, she did.\" (did = completed the analysis)
\"Has the paper been accepted?\" \"No, it hasn't.\" (hasn't = has not been accepted)

3. Pro-Adverbialsverbs (Adverb Phrase Substitutes)

Pro-adverbials substitute for adverb phrases or prepositional phrases expressing time, place, or manner.

A. Place Pro-Forms: Here, There, Where

Here — deictic place pro-form pointing to the location of the speaker:

She works here. (at this place)
Come here. (to this place)
Here is where the anomaly was detected.

There — deictic place pro-form pointing to a location away from the speaker; also anaphoric:

She conducted the fieldwork there. (at that place)
Go there. (to that place)
She described the laboratory, and there the most significant finding was made. (anaphoric — the laboratory just mentioned)

Where — interrogative and relative place pro-form:

Where was the experiment conducted? (interrogative)
The laboratory where she worked was recently renovated. (relative)
Where there is data, there is the possibility of analysis. (generic/conditional)

Somewhere, anywhere, everywhere, nowhere — indefinite place pro-forms:

She left the samples somewhere in the laboratory.
The effect appeared everywhere the methodology was applied.
There is nowhere in the literature that addresses this directly.

Here and there are among the most versatile words in English, functioning as deictic place pro-forms, as existential subjects (there is, there are), as discourse markers (here is the main argument), and as emphatic focus particles (here she is).

B. Time Pro-Forms: Now, Then, When

Now — deictic time pro-form pointing to the present moment:

She is analyzing the data now. (at the present time)
Now is the time to draw conclusions. (the present moment is the appropriate time)
Now also functions as a discourse marker (discussed in the conjunction and adverb articles)

Then — deictic time pro-form pointing to a past or future time already established in the discourse:

She submitted the paper in March. Then she waited for the reviews. (then = at that time — March)
If the replication succeeds, then the hypothesis is confirmed. (then = at that point, as a consequence)

When — interrogative and relative time pro-form:

When was the study published? (interrogative)
The period when the data was collected was particularly productive. (relative)

Whenever — indefinite time pro-form:

Whenever the experiment was repeated, the results were consistent.

Sometimes, always, never, often, rarely — these are more accurately classified as frequency adverbs (discussed in the adverb article) than pro-forms, since they do not substitute for an antecedent.

C. Manner Pro-Forms: So, Thus, Thereby, How

So — manner pro-form substituting for a manner adverb or prepositional phrase:

She analyzed the data carefully, and in doing so she discovered an anomaly. (so = carefully, in that manner)
He proceeded methodically; she did so as well. (so = methodically)
If this is so, the implications are significant. (so = true in the manner described)

Thus — formal manner pro-form, substituting for a described process or manner; also expressing result:

She isolated the variable and thus controlled for its effect. (in that way)
The controls were in place; thus the results are reliable. (as a result of this)
Thus far the evidence is inconclusive. (up to this point)

Thereby — formal manner pro-form expressing instrumentality:

She refined the methodology, thereby eliminating the main source of error. (by doing that)
He acknowledged the limitation, thereby strengthening rather than weakening his argument.

How — interrogative manner pro-form:

How was the methodology validated?
She described how the experiment was conducted. (relative/indirect question)

4. Pro-Adjectivals (Adjective Phrase Substitutes)

Pro-adjectivals substitute for adjective phrases. This is the least developed substitution category in English — the language does not have a robust set of dedicated pro-adjectival forms — but several forms function in this capacity in specific contexts.

A. So as Pro-Adjectival

So can substitute for an adjective phrase in certain constructions, particularly after if and in comparatives:

The methodology is rigorous, and if so, the results are reliable. (so = rigorous in that way)
She is brilliant, and he is equally so. (so = brilliant)
The findings are significant — or at least she believes them to be so. (so = significant)

B. Such as Pro-Adjectival

Such substitutes for an adjective or a class-defining modifier:

She described the methodology as flawed. Such a methodology cannot produce reliable results. (such = of the kind just described — flawed)
He is a rigorous researcher. I have always admired such dedication. (such = of that kind)

C. The Same as Pro-Adjectival

The same can substitute for an attributive adjective phrase:

She used a rigorous methodology, and he used the same. (the same = the same rigorous methodology)

5. Pro-Clauses (Clause Substitutes)

Pro-clauses substitute for entire propositions — full clauses or sentences that have been stated or implied in the discourse.

A. So and Not (Repeated from Pro-Verbals)

As discussed under pro-verbals, so and not substitute for entire clause-level propositions after verbs of saying, thinking, and believing: I think so, I hope not, she said so.

B. This, That, It as Pro-Clauses

The demonstratives this and that and the pronoun it frequently substitute for entire clauses or propositions rather than for individual noun phrases:

That as pro-clause (anaphoric — referring back):

The replication failed. That was unexpected.
She proposed a new interpretation. That changed everything.
He refused to disclose the data. That raised serious concerns.

This as pro-clause (can be anaphoric or cataphoric):

The controls were inadequate and the sample was small. This undermines the entire argument. (anaphoric — refers back to the preceding statements)
This is the central claim: the methodology was fundamentally flawed. (cataphoric — anticipates what follows)

It as pro-clause (anaphoric, typically more tightly integrated):

She completed the analysis early. It surprised everyone. (it = the fact that she completed it early)
He published without peer review. It was a mistake. (it = the action of publishing without peer review)

The This vs. That vs. It Distinction for Clausal Reference:

These three forms differ in how they handle the antecedent clause:

This — treats the antecedent as proximate and immediate; often used to characterize a situation as salient or present:

The data was misrepresented. This is unacceptable.

That — treats the antecedent as established and perhaps more remote; a more neutral or distancing reference:

The data was misrepresented. That was unfortunate.

It — treats the antecedent as already integrated into the discourse; the most cohesive and least marked option for referring back to a described event or fact:

The data was misrepresented. It became the central issue in the inquiry.

C. If So, If Not, Otherwise as Conditional Pro-Clauses

These forms substitute for a conditional clause by referring back to a proposition and treating it as a condition:

If so — if the preceding proposition is true:

The methodology may have been compromised. If so, the results cannot be trusted. (if so = if the methodology was compromised)

If not — if the preceding proposition is false:

The controls must be maintained. If not, the results will be meaningless. (if not = if the controls are not maintained)

Otherwise — if the preceding proposition fails to hold; often with an implication of consequence:

The data must be verified. Otherwise, no conclusions can be drawn. (otherwise = if the data is not verified)

6. Reference Types Across Pro-Forms

All pro-forms establish reference through one of three mechanisms, and understanding these mechanisms is essential for understanding how pro-forms create cohesion in discourse.

A. Anaphoric Reference

Anaphoric pro-forms refer back to something already established in the preceding discourse — their antecedent precedes them. This is the most common type of pro-form reference and the primary mechanism of discourse cohesion:

A study was published last year. It challenged the consensus. (it refers back to a study)
She completed the analysis. This took three months. (this refers back to the completing of the analysis)
He went to the laboratory and worked there all night. (there refers back to the laboratory)
She was brilliant, and everyone knew it. (it refers back to her brilliance)

B. Cataphoric Reference

Cataphoric pro-forms refer forward to something that will be specified later in the discourse — their antecedent follows them. This is less common than anaphoric reference but creates a particular kind of forward tension and anticipation:

This is the central problem: the data was never independently verified. (this anticipates the following specification)
It surprised everyone that the replication failed. (it anticipates the that-clause)
Here is what she found: ...

C. Deictic Reference

Deictic pro-forms point to entities in the physical context of the utterance rather than in the surrounding discourse — they are anchored to the speech situation rather than to the text:

Here is the sample I was describing. (here points to the physical location)
That is the equipment we ordered. (that points to something visible in the shared context)
Now is the time to draw conclusions. (now points to the present moment of speaking)
This is what I mean. (this points to something being demonstrated or shown)