2.5 Logical Agreement: Faulty Predication, Mixed Constructions & Illogical Shifts
Key Takeaways
- Logical agreement is a separate blueprint item from concord: a sentence can be perfectly grammatical in form and still assert something its own subject and predicate cannot logically say.
- Faulty predication occurs when a subject cannot perform or equal its complement, as in 'The reason for the delay is because the sensor failed'; the standard repairs are 'is that' or dropping 'the reason' entirely.
- Definitions must equate a noun with a noun, so 'A recession is when output falls' becomes 'A recession is a period in which output falls' on the CLEP.
- A mixed construction begins with a prepositional or subordinate structure and then treats it as the grammatical subject, as in 'By raising fees generated new revenue'; deleting the opening preposition usually repairs it.
- Contrary-to-fact conditionals use 'had' in the if-clause and 'would have' only in the result clause: 'If the committee had met, it would have voted' — never 'If the committee would have met.'
2.5 Logical Agreement: Faulty Predication, Mixed Constructions & Illogical Shifts
Quick Reference: The College Board blueprint lists logical agreement as its own tested item under Conventions of Standard Written English, separate from concord. Concord asks whether the forms match — singular subject, singular verb. Logical agreement asks whether the meanings match: can this subject actually perform this verb, and can it actually equal this complement? A sentence such as The reason the trial failed is because the control group was contaminated violates no rule of number, tense, or case, yet it is still wrong, because the reason cannot equal because. The CLEP tests four families of this error: faulty predication, mixed constructions, illogical shifts, and incomplete or unbalanced comparisons.
These items are among the most frequently missed on the Conventions section precisely because they sound acceptable in speech. Your ear will not catch them. You have to test the sentence's logic deliberately: strip it to its subject, verb, and complement, and ask whether that skeleton makes sense on its own.
1. Faulty Predication: When the Subject Cannot Equal the Complement
Predication is the relationship between a subject and what the sentence says about it. Faulty predication occurs when a linking verb (is, are, was, were, becomes, seems) joins a subject to a complement that it cannot logically be.
The 'Reason ... Is Because' Trap
This is the single most heavily tested logical-agreement error in first-year composition.
- Flawed:
The reason the archaeological survey was suspended is because the monsoon season began early. - Diagnosis: The reason is a noun. Because the monsoon season began early is an adverbial clause answering why. A noun cannot equal an adverbial clause, and reason and because duplicate the same idea.
- Repair A (noun clause):
The reason the archaeological survey was suspended is **that** the monsoon season began early. - Repair B (delete the frame):
The archaeological survey was suspended **because** the monsoon season began early.— the more economical answer, and usually the keyed one.
The same defect appears with the explanation is because, my justification is because, and the cause is due to the fact that.
The 'Is When' and 'Is Where' Definition Trap
A definition equates a noun with a noun. Substituting an adverbial clause of time or place breaks that equation.
- Flawed:
Nominalization is when a writer converts a verb into an abstract noun. - Diagnosis: Nominalization is not a moment in time; the sentence promises a definition and delivers a clock reading.
- Correct:
Nominalization is **the conversion of** a verb into an abstract noun. - Flawed:
An estuary is where a river meets the tide. - Correct:
An estuary is **a coastal zone in which** a river meets the tide.
Subject–Complement Mismatch
Watch for an abstract noun subject paired with a predicate that only a concrete agent could take.
- Flawed:
The purpose of the longitudinal study was designed to track adolescent literacy gains. - Diagnosis: A purpose cannot be designed; the study was designed.
- Repair A:
The **purpose** of the longitudinal study **was to track** adolescent literacy gains. - Repair B:
The longitudinal **study was designed to track** adolescent literacy gains.
Other recurring mismatches include The book's argument disagrees with critics (an argument does not disagree; the author does) and The novel's setting takes place in Lagos (the action takes place; the setting is Lagos).
2. Mixed Constructions: Starting One Sentence and Finishing Another
A mixed construction begins with one grammatical pattern and abandons it mid-sentence, most often by taking a phrase that cannot be a subject and treating it as one.
- Flawed:
By increasing municipal parking fees generated an additional four million dollars in annual revenue. - Diagnosis: By increasing municipal parking fees is a prepositional phrase. Prepositional phrases cannot serve as grammatical subjects, so generated has no subject at all.
- Repair A (delete the preposition):
**Increasing** municipal parking fees generated an additional four million dollars in annual revenue. - Repair B (supply a real subject):
By increasing municipal parking fees, **the city** generated an additional four million dollars in annual revenue.
The same failure occurs with subordinate clauses pressed into subject position:
- Flawed:
Although the vaccine trial enrolled twelve thousand participants did not guarantee statistical power. - Repair:
**Enrolling** twelve thousand participants in the vaccine trial did not guarantee statistical power.
Exam tactic: When an answer option opens with By, Through, In, With, When, or Although, immediately locate the main verb and ask what noun performs it. If the only candidate sits inside the opening phrase, the option is a mixed construction and can be eliminated without reading further.
3. Illogical Shifts in Number, Tense, and Mood
Distributive Number Logic
When each member of a group possesses one of something, standard usage keeps both nouns singular or makes both plural — never one of each.
- Flawed:
Each of the delegates submitted their credentials to the chair.(singular each, plural their) - Flawed:
All twelve jurors raised **their hand**.(twelve people, one hand) - Correct:
All twelve jurors raised **their hands**. - Correct:
**Each delegate** submitted **his or her** credentials to the chair.or**The delegates** submitted **their** credentials to the chair.
The 'One of the ... Who' Construction
The relative pronoun after one of the refers to the plural noun, not to one.
She is one of the few economists **who have** predicted the contraction.(who = economists, plural)She is **the only one** of the economists **who has** predicted the contraction.(only one forces the singular)
Contrary-to-Fact Conditionals
The subjunctive conditional puts had in the if-clause and would have only in the result clause. Placing would have in both halves is a classic keyed error.
- Flawed:
If the review board would have examined the raw data, it would have caught the transcription error. - Correct:
**If the review board had examined** the raw data, it would have caught the transcription error. - Present unreal conditions take were for every person:
If the endowment **were** larger, the college could waive tuition.
4. Incomplete and Unbalanced Comparisons
Section 2.3 covered comparing unlike categories. Logical agreement adds the problem of the comparison that is never finished.
- Flawed:
The revised curriculum produces stronger writers.(Stronger than what?) - Correct:
The revised curriculum produces stronger writers **than the legacy sequence did**. - Flawed:
Antarctica is colder than any continent.(Antarctica is a continent, so it cannot be colder than itself.) - Correct:
Antarctica is colder than **any other** continent. - Flawed:
The archive holds more manuscripts than **the state library holds maps**.— grammatically fine but logically unbalanced if the point was manuscript volume; make the compared terms match.
Logical Agreement Diagnostic Table
| Error Family | Flawed Sentence | Why the Logic Fails | Exam-Ready Revision |
|---|---|---|---|
| Reason ... is because | The reason enrollment fell is because tuition rose. | A noun subject cannot equal an adverbial because-clause; reason and because also duplicate. | Enrollment fell because tuition rose. |
| Is when / is where | Inflation is when prices rise across an economy. | A definition must equate noun to noun, not noun to a time clause. | Inflation is a sustained rise in prices across an economy. |
| Subject–complement mismatch | The goal of the initiative was created to reduce food waste. | A goal cannot be created to act; the initiative was. | The initiative was created to reduce food waste. |
| Mixed construction | Through analyzing the sediment cores revealed three volcanic layers. | The prepositional phrase is standing in for a subject that does not exist. | Analyzing the sediment cores revealed three volcanic layers. |
| Distributive number | Every violinist tuned their instrument. | Singular distributive subject paired with a plural possessive. | The violinists tuned their instruments. |
| Faulty conditional | If the pilot would have descended sooner, the icing would have cleared. | Would have cannot occupy the if-clause of a contrary-to-fact condition. | If the pilot had descended sooner, the icing would have cleared. |
| Incomplete comparison | Community colleges are more affordable. | The second term of the comparison is missing entirely. | Community colleges are more affordable than four-year public universities. |
| Illogical superlative | The Nile is longer than any river in Africa. | The Nile is an African river and cannot exceed itself. | The Nile is longer than any other river in Africa. |
Which revision best repairs the faulty predication in the following sentence? 'The reason the municipal bond referendum failed is because voters distrusted the projected maintenance costs.'
Which sentence contains a mixed construction?
Which of the following sentences observes standard logical agreement in a contrary-to-fact conditional?
Which sentence is free of illogical comparison and illogical number?