Basic Parts of a Sentence

I like the construction of sentences and the juxtaposition of words—not just how they sound or what they mean, but even what they look like.

—author Don DeLillo

Subject and Predicate

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.
    • Notice that the introductory phrase, “Although a majority of caffeine drinkers think of it as a stimulant,” is not a part of the subject or the predicate.
  • In a secure landfill, the soil on top and the cover block storm water intrusion into the landfill. (compound subject)
    • There are two subjects in this sentence: soil and cover.
  • Surrounding the secure landfill on all sides are impermeable barrier walls(inverted sentence pattern)
    • In an inverted sentence, the predicate comes before the subject. You won’t run into this sentence structure very often as it is pretty rare.

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

  • The pressure in a pressured water reactor varies from system to system.
  • In contrast, a boiling water reactor operates at constant pressure.
  • The pressure is maintained at about 2250 pounds per square inch then lowered to form steam at about 600 pounds per square inch. (compound predicate)
    • There are two predicates in this sentence: “is maintained at about 2250 pounds per square inch” and “lowered to form steam at about 600 pounds per square inch”

Practice

Identify the subject and predicate of each sentence:

  1. Daniel and I are going to go to Hawaii for three weeks.
  2. Raquel will watch the dogs while we’re on vacation.
  3. She will feed the dogs and will make sure they get enough exercise.

A predicate can include the verb, a direct object, and an indirect object.

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 activityshift 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.

Note: Objects can belong to any verb in a sentence, even if the verbs aren’t in the main clause. For example, let’s look at the sentence “When you give your teacher your assignment, be sure to include your name and your class number.”

  • Your teacher is the indirect object of the verb give.
  • Your assignment is the direct object of the verb give.
  • Your name and your class number are the direct objects of the verb include.

Practice

Identify the objects in the following sentences. Are they direct or indirect objects?

  1. The cooler temperatures brought about by nuclear war might end all life on earth.
  2. 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.
  3. In your application letter, tell the potential employer that a resume accompanies the letter.

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

All of these clauses are dependent clauses. As we learned in Conjunctions, any clause with a subordinating conjunction is a dependent clause. For example “I was a little girl in 1995” is an independent clause, but “Because I was a little girl in 1995” is a dependent clause. Subordinating conjunctions include the following:

after although as as far as as if as long as as soon as
as though because before even if even though every time if
in order that since so so that than though unless
until when whenever where whereas wherever  while

Let’s look at the other clause from our examples:

  • which, if current plans hold, will bring nuclear capacity to about 22% of all electrical capacity by 1995

This clause starts with the relative pronoun which (see Relative Pronouns for more information on these). Any clause prefaced with a relative pronoun becomes a dependent clause.

Practice

In each of the following sentences, identify their phrases, dependent clauses, and independent clauses:

  1. Because Dante won the steamboat competition, he let Maxwell win the rowing race.
  2. That truck with the missing tires looks really old.
  3. Why can’t I read The Martian?
  4. Swimming across the English Channel in nearly twenty-three hours, Laís set a new personal record.
  5. Whenever I see Alice and Armando’s Instagram account, The Two of Us, I’m overwhelmed with feelings.