The Four Logical Relationships - SENTENCE COMPLETION SKILLS - SAT Test Prep

SAT Test Prep


Lesson 2: The Four Logical Relationships

Logic Is as Important as an Enormous Vocabulary

The Sentence Completion questions on the SAT are logical questions. That is, they are asking you to find the best word or phrase to complete each thought logically. They are not asking you to find the “most interesting” or the “most complicated” word or phrase. Each question will include only one choice that will complete the sentence in a way that makes logical sense. The other choices will be illogical or incomplete in one way or another.


What Mr. Harrison”s writing lacked in clarity it made up for in------- , for it contained enough information for a clever craftsman to re-create his invention down to the most minute detail.

At first reading, it may seem as if there are many different ways of completing the sentence. That is, there are many ways that a piece of writing might make up for a lack of clarity: it might be clever, or funny, or useful, or thought-provoking. But when you look at the sentence as a whole, there is only one logical way to complete the sentence. The second part of the sentence is key: it says that his writing contains enough information for a clever craftsman to re-create his invention down to the most minute detail. In other words, it provides a lot of detail. This must be what makes up for its lack of clarity! So while there are many “good” ways to complete the sentence, only a word like meticulousness, comprehensiveness, completeness, detail, etc., will make the sentence logically complete.

The Logical Structure of a Sentence

Every sentence in a Sentence Completion question has a logical structure that shows the logical relationship among the ideas in the sentence. That scheme will always include one or more of the four basic logical relationships.


e.g. Although we waited over two hours for a table, it seemed like only a few minutes.


e.g. We loved staying at the cottage; the sounds of the ocean calmed us and the sea air invigorated us.

Cause and Effect

e.g. We were irritated by the noise, so we moved to the next room.

Definition or Explanation

e.g. Joel was a nihilist, someone who doesn”t believe that any truth is absolute.

Many sentences include more than one logical structure. Think carefully about each sentence and make sure you see all of the logical relationships.


The motion of the region”s glaciers is both ------ and ------: they seem not to be moving at all, yet they transform the landscape more profoundly than any other force of nature.

When you first read the phrase both ------ and ------, it may seem that the two missing words must be similar, because they are joined with and rather than but or yet. But you must get the overall logical structure first. The colon indicates that the two statements support each other, and the use of yet in the second statement shows a contrast between the two ideas within the second statement. Therefore, the first missing word should mean seemingly motionless, and the second word should mean something like having a profound effect. Imperceptible and dramatic work nicely.

Concept Review 2: The Four Logical Relationships

1. What are the four basic logical relationships a sentence may include?

After each sentence, describe its “logical structure” by circling each logical relationship—contrast, support, cause and effect, or definition—that you can find within the sentence. (Remember that a sentence may show more than one relationship.)

2. Although he clearly was obsessed with the ------ of moral integrity, he was also aware of its potential -------: self-righteousness, arrogance, and condescension.

3. Few of us appreciated our group leader”s ------; we were too intelligent and had too much self-esteem to be persuaded by her constant use of insult and humiliation.

4. In need of a ------ from persecution, many young refugees wandered far from their homeland seeking ------ communities in which to settle.

5. Because the population of bacteria soon ------ the food supply, their once rapid proliferation soon slows, and may even stop altogether.

6. Deer in the wild often seem ------ to the concept of death; they are utterly unaware of any danger even when they notice their friends nearby dropping one by one.

7. Some contend that the quatrains of Nostradamus ------ events that would not take place for centuries, including ------ like wars, conflagrations, and earthquakes.

8. While the script for the movie consummately depicted the wit and charm of Oscar Wilde, the incompetent actor portraying him mutilated the most ------ lines.

9. The herd of lemmings always acted ------, thus ensuring that either they all survived or they all perished.

10. By ------ his announcement of the new promotions, Carl felt that he could maintain his employees” eagerness with the element of anticipation.

SAT Practice 2: The Four Logical Relationships

1. Possessing seemingly boundless energy, DeVare fights for the causes she supports with a ------ that would leave others ------ at the end of the workday.

(A) grace . . scandalized

(B) commitment . . uncertain

(C) loyalty . . contrite

(D) vigor . . exhausted

(E) sincerity . . disillusioned

2. The members of the committee saw Vance”s reign as chairman becoming more and more ------; his decisions seemed based more on personal whim than on the opinions of his fellow members.

(A) inclusive

(B) abstract

(C) irresistible

(D) illusory

(E) arbitrary

3. The boundary between Canada and the United States is more a political than a cultural ------; the people on both sides ------ a great deal in terms of artistic sensibilities.

(A) demarcation . . share

(B) partition . . estrange

(C) event . . partake

(D) affiliation . . admit

(E) division . . conflict

4. Some criminal investigators believe that polygraphs reliably ------ deception by recording ------ reactions in a subject such as slight changes in breathing rate or perspiration elicited by a set of questions.

(A) judge . . imaginative

(B) detect . . physiological

(C) predict . . imperceptible

(D) subvert . . simulated

(E) induce . . verifiable

5. The author intentionally combines the vernacular of the Bronx with pretentious academic jargon, creating a uniquely ------ style that makes her novel particularly difficult to translate into other languages.

(A) mundane

(B) taciturn

(C) alliterative

(D) idiosyncratic

(E) orthodox

6. The fact that polar bears are tremendously strong indicates the degree of ------ they must have in their aggressive play, for they never hurt each other.

(A) intensity

(B) stamina

(C) concentration

(D) instinct

(E) restraint

7. Long an advocate of deterrence, General Wallace had hoped that the ------ display of force would ------ further military action.

(A) formidable . . obviate

(B) subtle . . require

(C) impressive . . generate

(D) unnecessary . . prevent

(E) unbridled . . sustain

8. Disillusioned and ------, the impoverished young writer was ready to ------ the artistic life for a real job.

(A) capable . . abandon

(B) complacent . . invoke

(C) dejected . . forsake

(D) gracious . . deny

(E) crushed . . capture

9. The meal of raw eggs and vegetables, while ------, in fact ------ all requisite nutrition to the young athlete in training.

(A) meager . . denied

(B) sumptuous . . supplied

(C) spartan . . provided

(D) doleful . . restored

(E) appropriate . . allowed

Answer Key 2: The Four Logical Relationships

Concept Review 2

1. support, contrast, cause and effect, and definition

2. support (colon indicates examples), contrast (although)

3. support (semicolon indicates development), definition (missing word means constant use of insult and humiliation)

4. support (------ communities must provide ------ from persecution), cause and effect (the need caused their search)

5. cause and effect (because)

6. definition (missing word means utterly unaware)

7. support (examples are given)

8. support (the script was consummate so the lines must have been good, too), contrast (while)

9. cause and effect (thus)

10. cause and effect (by …)

SAT Practice 2

1. D Boundless energy is the definition of vigor. This is the kind of thing that would cause someone to be exhausted at the end of the day.

grace = elegance; scandalized = shamed publicly; contrite = filled with regret; vigor = great energy; disillusioned = with lowered esteem for another

2. E This sentence contains a definition. The missing word means based more on personal whim than on the opinions of his fellow members. This is what arbitrary means.

inclusive = including; abstract = not concrete; illusory = based on or characteristic of illusion; arbitrary = based on whim or random power

3. A The semicolon indicates support. The phrase more … than … indicates a contrast. The word boundary is the definition of the first missing word.

demarcation = boundary; estrange = cause to grow apart; partake = participate; affiliation = close association

4. B Such as indicates support through example. Breathing rate and perspiration are examples of physiological reactions. (They aren”t imperceptible because they”re being recorded!) The word by indicates a cause and effect relationship. The recording of such reactions would not induce(cause) deception, but might just detect it.

imperceptible = incapable of being detected; subvert = undermine; simulated = artificial; induce = cause; verifiable = capable of being proven true

5. D The sentence shows a cause and effect: something about the novel makes it (causes it to be) difficult to translate. The description makes it sound quirky, which would indeed make it hard to translate.

mundane = ordinary; taciturn = not talkative; alliterative = tending to use words that begin with the same sound; idiosyncratic = quirky; orthodox = adhering strictly to teachings

6. E This sentence shows a cause and effect. Some quality of the bears causes them not to hurt each other, even in aggressive play. Particularly since they are so strong, they would have to have a lot of restraint.

stamina = endurance; concentration = focus; instinct = inborn ability; restraint = ability to hold back

7. A This sentence supports the main idea with a description of the General”s beliefs. Deterrence is the belief that a strong offensive capability will deter (prevent) attack from one”s enemies, that is, that a formidable (awesome) display of force would obviate (render unnecessary through foresight) further military action.

subtle = hard to detect; unbridled = lacking restraint

8. C This sentence supports the main idea with a description of the writer”s mood. If a writer is disillusioned and impoverished, she would probably not want to stay in that situation for much longer. She would want to give up the artistic life. The first word should be a negative adjective that describes the life she wants to give up.

complacent = self-satisfied; invoke = call in; dejected = sad; forsake = abandon; gracious = full of grace

9. C The word while and the phrase in fact indicate a contrast. A meal of raw eggs and vegetables sounds pretty minimal, but it must provide all requisite (necessary) nutrition to the young athlete.

meager = minimal; sumptuous = bountiful; spartan = minimal, stark; doleful = sad