Writing Grammatically Correct Sentences

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Writing Grammatically Correct Sentences

Grammar is the study of how words can be combined into sentences to make meaning. Why does it matter if you can write grammatically correct sentences? One reason is that many grammar conventions are functional. If you write, “After sitting on a mildewed shelf in the garage for thirty years, my brother decided to throw out the old computer,” you’ve said that your brother spent thirty years sitting on a mildewed shelf in the garage, which gave him plenty of time to decide what to do with the old computer. If you write, “Did Sean tell Liam when he was expected to report to work?” the reader might have a hard time figuring out whether he refers to Sean or Liam.

Even if a grammar mistake doesn’t make you sound silly or confuse the reader, it can hurt you by making readers doubt your credibility. The logic is that if you are careless about grammar, you might also be careless about the quality of the technical information you communicate. Many readers will assume that documents that are unprofessional because of grammar problems might also be unprofessional in other ways.

This section will review nine principles for using clear, correct grammar:

AVOID SENTENCE FRAGMENTS

A sentence fragment is an incomplete sentence. A sentence fragment occurs when a sentence is missing either a verb or an independent clause. To correct a sentence fragment, use one of the following two strategies:

1. Introduce a verb.

FRAGMENT The pressure loss caused by a worn gasket.
This example is a fragment because it lacks a verb. (The word caused does not function as a verb here; rather, it introduces a phrase that describes the pressure loss.)
COMPLETE The pressure loss was caused by a worn gasket.
Pressure loss now has a verb: was caused.
COMPLETE We identified the pressure loss caused by a worn gasket.
Pressure loss becomes the object in a new main clause: We identified the pressure loss.
FRAGMENT A plotting program with clipboard plotting, 3D animation, and FFTs.
COMPLETE It is a plotting program with clipboard plotting, 3D animation, and FFTs.
COMPLETE A plotting program with clipboard plotting, 3D animation, and FFTs will be released today.

2. Link the fragment (a dependent element) to an independent clause.

FRAGMENT The article was rejected for publication. Because the data could not be verified.
Because the data could not be verified is a fragment because it lacks an independent clause: a clause that has a subject and a verb and could stand alone as a sentence. To be complete, the clause needs more information.
COMPLETE The article was rejected for publication because the data could not be verified.
The dependent element is joined to the independent clause that precedes it.
COMPLETE Because the data could not be verified, the article was rejected for publication.
The dependent element is followed by the independent clause.
FRAGMENT Delivering over 150 horsepower. The two-passenger coupe will cost over $32,000.
COMPLETE Delivering over 150 horsepower, the two-passenger coupe will cost over $32,000.
COMPLETE The two-passenger coupe will deliver over 150 horsepower and cost over $32,000.
AVOID COMMA SPLICES

A comma splice is an error that occurs when two independent clauses are joined, or spliced together, by a comma. Independent clauses in a comma splice can be linked correctly in three ways:

1. Use a comma and a coordinating conjunction (and, or, nor, but, for, so, or yet).

SPLICE The 909 printer is our most popular model, it offers an unequaled blend of power and versatility.
CORRECT The 909 printer is our most popular model, for it offers an unequaled blend of power and versatility.
The coordinating conjunction for explicitly states the relationship between the two clauses.

2. Use a semicolon.

SPLICE The 909 printer is our most popular model, it offers an unequaled blend of power and versatility.
CORRECT The 909 printer is our most popular model; it offers an unequaled blend of power and versatility.
The semicolon creates a somewhat more distant relationship between the two clauses than the comma and coordinating conjunction do; the link remains implicit.

3. Use a period or another form of terminal punctuation.

SPLICE The 909 printer is our most popular model, it offers an unequaled blend of power and versatility.
CORRECT The 909 printer is our most popular model. It offers an unequaled blend of power and versatility.
The two independent clauses are separate sentences. Of the three ways to punctuate the two clauses correctly, this one suggests the most distant relationship between them.
AVOID RUN-ON SENTENCES

In a run-on sentence (sometimes called a fused sentence), two independent clauses appear together with no punctuation between them. A run-on sentence can be corrected in the same three ways as a comma splice:

1. Use a comma and a coordinating conjunction (and, or, nor, but, for, so, or yet).

RUN-ON The 909 printer is our most popular model it offers an unequaled blend of power and versatility.
CORRECT The 909 printer is our most popular model, for it offers an unequaled blend of power and versatility.

2. Use a semicolon.

RUN-ON The 909 printer is our most popular model it offers an unequaled blend of power and versatility.
CORRECT The 909 printer is our most popular model; it offers an unequaled blend of power and versatility.

3. Use a period or another form of terminal punctuation.

RUN-ON The 909 printer is our most popular model it offers an unequaled blend of power and versatility.
CORRECT The 909 printer is our most popular model. It offers an unequaled blend of power and versatility.
AVOID AMBIGUOUS PRONOUN REFERENCES

Pronouns must refer clearly to their antecedents—the words or phrases they replace. To correct ambiguous pronoun references, use one of these four strategies:

1. Clarify the pronoun’s antecedent.

UNCLEAR Remove the cell cluster from the medium and analyze it.
Analyze what: the cell cluster or the medium?
CLEAR Analyze the cell cluster after removing it from the medium.
CLEAR Analyze the medium after removing the cell cluster from it.
CLEAR Remove the cell cluster from the medium. Then analyze the cell cluster.
CLEAR Remove the cell cluster from the medium. Then analyze the medium.

2. Clarify the relative pronoun, such as which, introducing a dependent clause.

UNCLEAR She decided to evaluate the program, which would take five months.
What would take five months: the program or the evaluation?
CLEAR She decided to evaluate the program, a process that would take five months.
By replacing which with a process that, the writer clearly indicates that it is the evaluation that will take five months.
CLEAR She decided to evaluate the five-month program.
By using the adjective five-month, the writer clearly indicates that it is the program that will take five months.

3. Clarify the subordinating conjunction, such as where, introducing a dependent clause.

UNCLEAR This procedure will increase the handling of toxic materials outside the plant, where adequate safety measures can be taken.
Where can adequate safety measures be taken: inside the plant or outside?
CLEAR This procedure will increase the handling of toxic materials outside the plant. Because adequate safety measures can be taken only in the plant, the procedure poses risks.
CLEAR This procedure will increase the handling of toxic materials outside the plant. Because adequate safety measures can be taken only outside the plant, the procedure will decrease safety risks.
Sometimes the best way to clarify an unclear reference is to split the sentence in two, drop the subordinating conjunction, and add clarifying information.

4. Clarify the ambiguous pronoun that begins a sentence.

UNCLEAR Allophanate linkages are among the most important structural components of polyurethane elastomers. They act as cross-linking sites.
What act as cross-linking sites: allophanate linkages or polyurethane elastomers?
CLEAR Allophanate linkages, which are among the most important structural components of polyurethane elastomers, act as cross-linking sites.
The writer has rewritten part of the first sentence to add a clear nonrestrictive modifier and has combined the rewritten phrase with the second sentence.

If you begin a sentence with a demonstrative pronoun that might be unclear to the reader, be sure to follow it immediately with a noun that clarifies the reference.

UNCLEAR The new parking regulations require that all employees pay for parking permits. These are on the agenda for the next senate meeting.
What are on the agenda: the regulations or the permits?
CLEAR The new parking regulations require that all employees pay for parking permits. These regulations are on the agenda for the next senate meeting.
COMPARE ITEMS CLEARLY

When comparing or contrasting items, make sure your sentence communicates their relationship clearly. A simple comparison between two items usually causes no problems: “The X3000 has more storage than the X2500.” Simple comparisons, however, can sometimes result in ambiguous statements:

AMBIGUOUS Trout eat more than minnows.
Do trout eat minnows in addition to other food, or do trout eat more than minnows eat?
CLEAR Trout eat more than minnows do.

If you are introducing three items, make sure the reader can tell which two are being compared:

AMBIGUOUS Trout eat more algae than minnows.
CLEAR Trout eat more algae than they do minnows.
CLEAR Trout eat more algae than minnows do.

Beware of comparisons in which different aspects of the two items are compared:

ILLOGICAL The resistance of the copper wiring is lower than the tin wiring.
LOGICAL The resistance of the copper wiring is lower than that of the tin wiring.
Resistance cannot be logically compared with tin wiring. In the revision, the pronoun that substitutes for resistance in the second part of the comparison.
USE ADJECTIVES CLEARLY

In general, adjectives are placed before the nouns that they modify: the plastic washer. In technical communication, however, writers often need to use clusters of adjectives. To prevent confusion in technical communication, follow two guidelines:

1. Use commas to separate coordinate adjectives. Adjectives that describe different aspects of the same noun are known as coordinate adjectives.

portable, programmable device

adjustable, removable housings

The comma is used instead of the word and.

Sometimes an adjective is considered part of the noun it describes: electric drill. When one adjective modifies electric drill, no comma is required: a reversible electric drill. The addition of two or more adjectives, however, creates the traditional coordinate construction: a two-speed, reversible electric drill.

2. Use hyphens to link compound adjectives. A compound adjective is made up of two or more words. Use hyphens to link these elements when compound adjectives precede nouns.

a variable-angle accessory

increased cost-of-living raises

The hyphens in the second example prevent increased from being read as an adjective modifying cost.

A long string of compound adjectives can be confusing even if you use hyphens appropriately. To ensure clarity, turn the adjectives into a clause or a phrase following the noun.

UNCLEAR an operator-initiated default-prevention technique
CLEAR a technique initiated by the operator to prevent default
MAINTAIN SUBJECT-VERB AGREEMENT

The subject and verb of a sentence must agree in number, even when a prepositional phrase comes between them. The object of the preposition might be plural in a singular sentence.

INCORRECT The result of the tests are promising.
CORRECT The result of the tests is promising.

The object of the preposition might be singular in a plural sentence.

INCORRECT The results of the test is promising.
CORRECT The results of the test are promising.

Don’t be misled by the fact that the object of the preposition and the verb don’t sound natural together, as in tests is or test are. Here, the noun test(s) precedes the verb, but it is not the subject of the verb. As long as the subject and verb agree, the sentence is correct.

MAINTAIN PRONOUN-ANTECEDENT AGREEMENT

A pronoun and its antecedent (the word or phrase being replaced by the pronoun) must agree in number. Often an error occurs when the antecedent is a collective noun—one that can be interpreted as either singular or plural, depending on its usage.

INCORRECT The company is proud to announce a new stock option plan for their employees.
CORRECT The company is proud to announce a new stock option plan for its employees.
Company acts as a single unit; therefore, the singular pronoun is appropriate.

When the individual members of a collective noun are emphasized, however, a plural pronoun is appropriate.

CORRECT The inspection team have prepared their reports.
CORRECT The members of the inspection team have prepared their reports.
The use of their emphasizes that the team members have prepared their own reports.
USE TENSES CORRECTLY

Two verb tenses are commonly used in technical communication: the present tense and the past perfect tense. It is important to understand the specific purpose of each.

1. The present tense is used to describe scientific principles and recurring events.

INCORRECT In 1992, McKay and his coauthors argued that the atmosphere of Mars was salmon pink.
CORRECT In 1992, McKay and his coauthors argued that the atmosphere of Mars is salmon pink.
Although the argument was made in the historical past—1992—the point is expressed in the present tense because the atmosphere of Mars continues to be salmon pink.

When the date of the argument is omitted, some writers express the entire sentence in the present tense.

CORRECT McKay and his coauthors argue that the atmosphere of Mars is salmon pink.

2. The past perfect tense is used to describe the earlier of two events that occurred in the past.

CORRECT We had begun excavation when the foreman discovered the burial remains.
Had begun is the past perfect tense. The excavation began before the burial remains were discovered.
CORRECT The seminar had concluded before I got a chance to talk with Dr. Tran.