Sentence Structure (CLASS B & C)

Basic Parts of a Sentence

Every sentence has a subject and a predicate. The subject of a sentence is the noun, pronoun, or phrase or clause the sentence is about:

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

The predicate is the rest of the sentence after the subject:

• The pressure in a pressured 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 pressure.

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.
  • The action (contains) is directly happening to the object (workings).
• 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 action (used) is directly happening to the object (discs).
• A 20 percent fluctuation in average global temperature could reduce biological activity, shift weather patterns, and ruin agriculture. (compound direct object)
  • The actions are directly happening to multiple objects: reduce activity, shift patterns, and ruin agriculture.
• On Mariners 6 and 7, the two-axis scan platforms provided much more capability and flexibility for the scientific payload than those of Mariner 4. (compound direct object)
  • The action (provided) is directly happening to multiple objects (capability and flexibility).

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.

• The company is designing senior citizens a new walkway to the park area.
  • The company is not designing new models of senior citizens; they are designing a new walkway for senior citizens. Thus, senior citizens is the indirect object of this sentence.
  • Walkway is the direct object of this sentence, since it is the thing being designed.
• Please send the personnel office a resume so we can further review your candidacy.
• You are not being asked to send the office somewhere; you’re being asked to send a resume to the office. Thus, the personnel office is the indirect object of this sentence.
• Resume is the direct object of this sentence, since it is the thing you should send.

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):

Phrases	Clauses
Electricity has to do with those physical phenomena involving electrical charges and their effects when in motion and when at rest.(involving electrical charges and their effects is also a phrase.)	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.
In 1833, Faraday’s experimentation with electrolysis indicated a natural unit of electrical charge, thus pointing to a discrete rather than continuous charge. (to a discrete rather than continuous charge is also a phrase.)	Since the frequency is the speed of sound divided by the wavelength, a shorter wavelength means a higher wavelength.
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.	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. (if current plans hold is a clause within a clause)

There are two types of clauses: dependent and independent. A dependent clauses is dependent on something else: it cannot stand on its own. An independent clause, on the other hand, is free to stand by itself.

So how can you tell if a clause is dependent or independent? Let’s take a look at the clauses from the table above:

• when two oppositely charged bodies are brought close to one another
• Since the frequency is the speed of sound divided by the wavelength
• which, if current plans hold, will bring nuclear capacity to about 22% of all electrical capacity by 1995

Common Sentence Structures

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.
• The cross-member exposed to abnormal stress eventually broke.
• Only two types of charge exist in nature.

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.

Subject + verb + indirect object + direct object

The sentence pattern with the indirect object and direct object is similar to the preceding pattern:

• I am writing her about a number of problems that I have had with my computer.
• Austin, Texas, has recently built its citizens a system of bike lanes.