Online Technical Writing: Basic Patterns and Elements of the Sentence

Basic Sentence Patterns and Types Basic Parts of the Sentence Parts of Speech Phrases and Clauses This section is a quick review of the fundamentals of the sentence. If you encounter unfamiliar terminology in this book or in your class, refer to this section for help. For more on of sentence grammar, see English Fundamentals by Emery, Kierzek, and Lindblom (Macmillan), for a thorough discussion of sentence grammar, along with exercises.

Basic sentence patterns

Subject + verb. The simplest of sentence patterns is composed of a subject and verb without a direct object or subject complement. It uses an intransitive verb, that is, a verb requiring no direct object:

Control rods remain inside the fuel assembly of the reactor.

The development of wind power practically ceased until the early 1970s.

All amplitude-modulation (AM) receivers work in the same way.

The cross-member exposed to abnormal stress eventually broke.

Only two types of charge exist in nature.

Subject + linking verb + subject complement. Another simple pattern uses the linking verb, any form of the to be verb without an action verb:

The chain reaction is the basis of nuclear power.

The debate over nuclear power has often been bitter.

Folding and faulting of the earth's surface are important geologic 

Windspeed seems to be highest during the middle of the day.

The silicon solar cell can be difficult and expensive to manufacture.

Subject + verb + direct object. Another common sentence pattern uses the direct object:

Silicon conducts electricity in an unusual way.

The anti-reflective coating on the the silicon cell reduces reflection 
from 32 to 22 percent.

Prestressing of the concrete increases the load-carrying capacity of 
the members.

Subject + verb + indirect object + direct object. The sentence pattern with the indirect object and direct object is similar to the preceding pattern:

We are sending you the balance of the payment in this letter.

I am writing her about a number of problems that I have had
with my Execucomp wordprocessor.

The supervisor mailed the applicant a description of the job.

I am writing you about a number of problems...

Austin, Texas, has recently built its citizens a system
of bikelanes.

Subject + verb + direct object + object complement. The sentence pattern using the [direct object] and object complement is not common but worth knowing):

The walls are usually painted black.

The plant shutdown left the entire area an economic disaster.

The committee declared the new design a breakthrough in
energy efficiency.

The low cost of the new computer made competition much too
difficult for some of the other companies.

Passive voice pattern. The passive voice is not ordinarily considered a "pattern," but it is an important and often controversial construction. It reverses the subject and object and, in some cases, deletes the subject. (See the section on problems with the weak use of the passive.) Compare these example active and passive voice sentences:

Passive voice                     Active voice
Saccharin is now permitted as     The FDA now permits saccharin
an additive in food.              as an additive in food.
This report is divided into       I have divided this report into
three main sections.              three main sections.
Windmills are classified as       Scientists classify windmills
either lift or drag types.        as either lift or drag types.
The valves used in engine         A computer usually controls the
start are controlled by a         valves used in an engine start.
The remains of Troy were des-     Later builders on the site of
troyed by later builders on       Troy destroyed the remains of
the the site.                     citadel.
Some restaurant locations can     You can lease some restaurant
be leased                         locations.

Simple sentences. A simple sentence is one that contains subject and a verb and no other independent or dependent clause.

To measure blood pressure, a device known as a
sphygmomanometer and a stethoscope are needed.
There are basically two types of stethoscopes.
The sphygmomanometer is usually covered with cloth and has two
rubber tubes attached to it.
One of the tubes is attached to the manometer part of the
instrument indicating the pressure of the air within the cuff.

Compound sentences. A compound sentence is made up of two or more independent clauses joined by a coordinating conjunction (and, or, nor, but, yet, for) and a comma, an adverbial conjunction and a semicolon, or a semicolon. The independent clauses must be simple sentences.

In sphygmomanometers, too narrow a cuff can result in
erroneously high readings, and too wide a cuff can result in
erroneously low readings.
Some cuff hook together; others wrap or snap into place.

Complex sentences. A complex sentence contains at least one dependent clause (a noun, adjective, or adverb clause) and no more than one independent clause:

A part of the stethoscope is the cuff, a rubber bag that can
be filled with air.
Inflate the cuff to about 40 mm Hg above the level at which
the radial pulse disappears.
That point at which you stop hearing heart sounds through the
stethoscope is the most reliable measure of diastolic
pressure, although it is usually somewhat above that found by
intra-arterial meaurements.
Because the blood moves in waves, there are two blood pressure
measures: the systolic pressure, which is the pressure of the
blood as a result of the contraction of the ventricles, and
the diastolic pressure, which is the pressure when the
ventricles are at rest.

Compound-complex sentences. A compound-complex sentence is made of two or more independent clauses and contains at least one dependent clause � in other words, a compound sentence with at least one dependent clause.

The systolic pressure is the pressure of the blood as a result
of the contraction of the ventricles, and the diastolic
pressure is the pressure when the ventricles are at rest.
The upper two chambers of the heart, which are called atria,
are thin-walled reservoirs; they readily distend to collect
blood that pours in from the veins between beats.

Basic parts of the sentence

Subject. The subject of a sentence is that noun, pronoun, or phrase or clause about which the sentence makes a statement.

Einstein's general theory of relativity has been subjected to
many tests of validity over the years.

Although a majority of caffeine drinkers think of it as a
stimulant, heavy users of caffeine say the substance relaxes

Surrounding the secure landfill on all sides are impremeable
barrier walls. (Inverted sentence pattern)

In a secure lanfill, the soil on top and the cover block storm
water intrusion into the landfill. (Compound subject)

Verb phrase. The main verb, or verb phrase, of a sentence is a word or words that express an action, event, or a state of existence. It sets up a relationship between the subject and the rest of the sentence.

The first high-level language to be widely accepted, FORTRAN,
was implemented on an IBM 704 computer.

Instruction in the source program must be translated into
machine language.

The operating system controls the translation of the source
program and carries out supervisory functions. (Compound verb)

Predicate. The predicate is the rest of the sentence coming after the subject. It can include the main verb, subject complement, direct object, indirect object, or object complement.

The pressure in a pressuried water reactor varies from system
to system.

The pressure is maintained at about 2250 pounds per square
inch to prevent steam from forming.

The pressure is then lowered to form steam at about 600 pounds
per square inch.

In contrast, a boiling water reactor operates at constant

Subject complement. The subject complement is that noun, pronoun, adjective, phrase, or clause that comes after a linking verb (some form of the be verb):

The maximum allowable concentration is ten parts H2S per
million parts breathable air.

The deadening of the sense of smell caused by H2S is the
result of the effects of H2S on the olfactory nerves of the

Continuous exposure to toxic concentrations of H2S can be

Direct object. A direct object � a noun, pronoun, phrase, or clause acting as a noun � takes the action of the main verb. A direct object can be identified by putting what?, which?, or whom? in its place.

The housing assembly of a mechanical pencil contains the
mechanical workings of the pencil.

Lavoisier used curved glass discs fastened together at their
rims, with wine filling the space between, to focus the sun's
rays to attain temperatures of 3000� F.

The dust and smoke lofted into the air by nuclear explosions
might cool the earth's atmosphere some number of degrees.

A 20 percent fluctuation in average global temperature could
reduce biological activity, shift weather patterns, and ruin

The cooler temperatures brought about by nuclear war might end
all life on earth.

On Mariners 6 and 7, the two-axis scan platforms provided much
more capability and flexibility for the scientific payload
than that of Mariner 4.

Indirect Object. An indirect object � a noun, pronoun, phrase, or clause acting as a noun � receives the action expressed in the sentence. It can be identified by inserting to or for.

In the application letter, tell [to] the potential employer
that a resume accompanies the letter.

The company is designing [for] senior citizens a new walkway
to the park area.

Do not send [to] the personnel office a resume unless someone
there specifically requests it.

Object complement. An object complement � a noun or adjective coming after a direct object � adds detail to the direct object. To identify object complements, insert [to be] between the direct object and object complement.

The superviser found the program [to be] faulty.

The company considers the new computer [to be] a major

Most people think the space shuttle [to be] a major step in
space exploration.

Parts of speech and other sentence elements

Nouns. A noun is the name of a person (Dr. Sanders), place (Lawrence, Kansas, factory, home), thing (scissors, saw, book), action (operation, irrigation), or idea (love, truth, beauty, intelligence). Remember that, while a word may look like a noun, it must function in the sentence as a noun:

The one experiment that has been given the most attention in
the debate on saccharin is the 1977 Canadian study done on

The Calorie Control Council, a group of Japanese and American
manufacturers of saccharin, spent $890,000 in the first three
months of the 1977 ban on saccharin on lobbying,
advertisements, and public relations.

A flat-plate collector located on a sloping roof heats water
which circulates through a coil and is pumped back to the

The blades start turning when the windspeed reaches 10 mph,
and an anemometer is attached to the shaft to measure

The multifuel capacity of the Stirling engine gives it a
versatility not possible in the internal combustion engine.

The regenerative cooling cycle in the engines of the Space
Shuttle is made up of high pressure hydrogen that flows in
tubes connecting the nozzle and the combustion chamber.

Pronouns. A pronoun stands in the place of a noun. There are several types: personal pronouns, demonstrative and indefinite pronouns, and relative and interrogative pronouns. Pronouns have antecedents, a reference to a word they take the place of.

Verbs. Traditionally, verbs are divided into four groups: active verbs, linking verbs, auxiliary verbs, and modals. Adjectives. An adjective provides more detail about a noun; that is, it modifies a noun. Adjectives occur just before the nouns they modify, or after a linking verb:

The armature is a rectangular ring about which another coil of
wire is wound.

The generator is used to convert mechanical energy into
electrical energy.

The steel pipes contain a protective sacrificial annode and
are surrounded by packing material.

Adverbs. An adverb provides more information about a verb, adjective, or another adverb; that is, it "qualifies" the verb, adjective, or adverb:

The desk is made of an especially corrosion-resistant
industrial steel.

The drilling bit actually tears rock apart to get at the oil.

The power company uses huge generators which are generally
turned by steam turbines.

The debate over nuclear power has often been bitter.

Conjunctions. Conjunctions link words, phrases, and whole clauses to each other and are divided into coordinating, adverbial, and subordinating conjunctions. In this list, only the coordinating conjunctions are complete:

   Coordinating          Subordinating        Adverbial
   conjunctions          conjunctions         conjunctions

     and                   although             therefore
     or                    since                however
     nor                   because              in other words
     but                   when                 thus
     yet                   while                then
     for                   if                   otherwise
     whereas               as if                nevertheless
                           as                   on the other hand

Phrases and clauses

Phrases and clauses are groups of words that act as a unit and perform a single function within a sentence. A phrase may have a partial subject or verb but not both; a dependent clause has both a subject and a verb (but is not a complete sentence). Here are a few examples (not all phrases are highlighted because some are embedded in others):


Electricity has to do with those physical phenomena involving
electrical charges and their effects when in motion and when at

Electricity manifests itself as a force of attraction, inde-
pendent of gravitational and short-range nuclear attraction,
when two oppositely charged bodies are brought close to one

In 1800, A. Volta constructed and experimented with the
voltaic pile, the predecessor of modern batteries.

In 1833, Faraday's experimentation with electrolysis
indicated a natural unit of electrical charge, thus pointing
to a discrete rather than continuous charge.

The symbol that denotes a connection to the grounding
conductor is three parallel horizontal lines, each of the
lower ones being shorter than the one above it.


Electricity manifests itself as a force of attraction,
independent of gravitational and short-range nuclear
attraction, when two oppositely charged bodies are brought
close to one another.

The symbol that denotes a connection to the grounding
conductor is three parallel horizontal lines, each of the
lower ones being shorter than the one above it.

These studies led Planck to postulate that electromagnetic
radiation is emitted in discrete amounts, called quanta.

Since the frequency is the speed of sound divided by the
wavelength, a shorter wavelength means a higher wavelength.

Nuclear units planned or in construction have a total capacity
of 186,998 KW, which, if current plans hold, will bring
nuclear  capacity to about 22 % of all electrical capacity by
1995. (A clause within a clause)

Prepositional phrases. A prepositional phrase, composed of a preposition and its object, shows relationships involving time, direction, or space:

An artificial heart was installed in a human subject for the
first time in 1969.

The current leads to the field coils and into an external

Alternators are not compatible with wind systems because of
their high rpm requirements.

The operation of a wind generator is based upon Faraday's law
of induced voltage which states that the voltage between the
ends of a loop of wire is proportional to the rate of change
in the magnetic field lines within the loop. (Four prepositional 
phrases in the last one highlighted.)

Appositives. An appositive, a word or phrase that renames a noun or pronoun, adds information about a noun but in a way different than do adjectives:

In 1972, Richard Nixon, president of the U.S.,  approved the
development of a reusable space vehicle, the Space Shuttle.
Broad principles about space flight were laid down by the
Austrian astronautical pioneer, Dr. Eugen Sanger.
The external tank of the Space Shuttle's main engines is
composed of two tanks � a large hydrogen tank and a smaller
oxygen tank.
An upper air inversion, a layer of stable air, is usually
present over large areas of the tradewinds as a hurricane

Participial phrases. A participial phrase is a group of words acting as an adjective and modifying a noun or pronoun. A participle is the -ed or -ing form of a verb:

The Eagle Generator uses a 6-pole, shunt-wound generator
designed to reach maximum power at 20 mph.

Because of the design created by Kwan-Gett, endothelial cells
could grow on the fibrin layer, making the interior surfaces
of the artificial heart similar to those of the natural heart.

The wire is wrapped around field cores made of steel lamina-

Gerunds and gerund phrases. Similar in appearance to a participial phrase, the gerund plays the role of noun. A gerund is a single word with -ing used as a noun. A gerund phrase is a single word with -ing accompanied by its objects, complements, and modifiers; it is a group of words acting as noun:

In the iron-core type transformer, the winding is wrapped
around an iron bar.

The splitting of an atom produces a great amount of energy.

The cloning of a cell produces an identical cell.

Jarvik changed his artificial heart design in 1974 by
fitting his model with a highly flexible three-layer diaphragm
made of smooth polyurethane.

The Jarvik-7 design then in 1979 achieved a record time of
sustaining life in a calf for 221 days.

Reversing the rotation of the electrohydraulic heart pump
reverses the direction of the hydraulic flow.

Adjective clauses. An adjective clause is almost a complete sentence � but not quite. It functions the same way a single-word adjective does: both modify, that is, add more information to our understanding of a noun. Adjective clauses contain (1) a relative pronoun, (2) in some cases, a subject, (3) a complete verb, and (4) any other accompanying predicates or objects:

Typically, one portable drilling rig, which requires two tug
boats to bring it to the site, and several other boats are
used in the exploratory drilling phase.

The company holds many patents on its wind energy systems,
such as the flyball governor which varies the pitch of the
blades in high winds and the slow-speed generator whose
performance curve matches that of the propeller.

The idea of the artificial heart arose in part from the need
to treat people who cannot receive a donor heart.

Nose designed a "biolized" heart in which the surfaces that
came into contact with blood were made from natural tissues
treated with chemical fixatives to make them tougher and
immunologically inert. (An adjective clause within another 
adjective clause)

The regular CPR class people are taking everywhere now only
lasts an evening.

Adverb clauses. An adverb clause is also nearly a complete sentence; it functions like an adverb does by explaining the how, when, where, and why of the discussion. The adverb clause usually contains a subordinating conjunction, a subject, a complete verb, and any other related phrases or clauses:

Because the shortage in donor hearts is so severe, transplant
surgery is limited to people with the best chances of
As long as the wind speed is sufficient, the electrical energy
will be continuously generated.
If an oil spill occurs away from shore, it is unlikely to
affect many birds, unless they are directly in a major
migratory path at a migrating season.

Noun clauses. A noun clause is a group of words used as a noun. Introduced by a relative pronoun, a noun clause can play any of the functions a noun plays: subject, direct object, object of preposition, subjective or object complement. Here are example noun clauses, with their functions labelled:

Estimates indicate that 20 million Americans owned hand-held
calculators by 1974. (direct object)

Computer systems are often measured by how much main memory
their architectures allow and by how fast that memory can
be accessed. (object of preposition - two of them!)

Lemaitre proposed that all matter in the Universe was once
concentrated into what he termed the primeval atom. (direct object; 
in this sentence, "what he termed the primeval atom" is also a noun

The choice of furnace wall construction depends on how
sophisticated the gas-cleaning equipment to be used is and on
whether a large amount of waste is to be recovered.
(object of preposition - two of them)
Most microcomputers use what are called flexible diskettes for
program and data storage. (direct object)
The major disadvantage of sequential files is that they are
slow. (subject complement)

Coordinated elements. Many of the sentence elements described above can be "coordinated"; that is, they can be doubled, tripled, or even quadrupled and linked with coordinating conjunctions like and and or. For example, in the phrase "a black and white Datsun 240Z," two adjectives are are coordinated. Here are some examples of coordinated sentence elements and their coordinating conjunctions:

In 1800, A. Volta constructed and experimented with the
voltaic pile, the predecessor of the modern battery. (two verb phrases)

Maxwell's theory not only synthesized theories about
electricity and magnetism, but also showed optics to be a
branch of electromagnetism. (two nouns and verb phrases)

Heat exchangers may be so designed that chemical reactions or
energy-generation processes can be carried out in them. (two noun phrases)

Heat exchangers find wide applications in the chemical process
industries, in the food industry, in the generation of steam
for production of power and electricity, in aircraft and space
vehicles, and in the field of cryogenics for low-temperature
separation of gases. (five prepositional phrases; two pairs of nouns)

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