Sentences: Parts and Patterns

This is Unit Two of College Composition. Unit One ended with a writer reading a prompt before drafting. This unit turns to the smallest complete unit a writer drafts: the sentence. Carry one idea through this lecture. Every sentence is built from clauses, and the way clauses are joined tells readers how the ideas relate. A worked example at the end arranges the same three facts in four structures. By the end you will be able to name the parts of a sentence. To tell independent clauses from dependent ones and the words that join them. To classify the four sentence structures. And to strip a long sentence to its core and diagnose it step by step.

Five entries on what every sentence needs: a subject, a predicate with a working verb, and the objects, complements and phrases that fill it out.

What makes a sentence complete.

CMP 0026 What a Sentence Needs

A complete sentence needs a subject and a predicate, and it must be able to stand alone. The subject names something; the predicate contains the verb, which expresses an action, an occurrence or a state of being. Length does not make a sentence complete; a long string of words without a working verb is still not a sentence.

Who or what the sentence is about.

CMP 0027 Subjects

The subject is the word or group of words a sentence is about, the doer or the thing described. In "The new library opens on Monday," the subject is the new library; its core is the single noun library. The subject is not always the first noun; in "Behind the desk sat a tired clerk," the subject is the clerk.

The heart of the predicate.

CMP 0028 Predicates and Verbs

The predicate is everything that says something about the subject, and its heart is the verb. In "The committee approved the budget after a long debate," the predicate begins at approved, and approved is the verb. A word ending in i n g is not a complete verb by itself; "the committee approving the budget" lacks one.

Receiving the action.

CMP 0029 Objects and Complements

Many sentences follow the pattern subject, verb, object: someone does something to something. In "The student revised the essay," the essay receives the action, so it is the object; in "The essay seemed stronger," stronger completes the subject instead. Readers follow the subject-verb-object pattern most easily, so burying it slows them down.

Groups of words that cannot stand alone.

CMP 0030 Phrases

A phrase is a group of related words that lacks a subject, a verb, or both, so it cannot stand alone. "After the long meeting" and "in the back of the room" are phrases; they add information to a sentence but are not sentences themselves. A sentence can hold many phrases and still be simple, because phrases do not add clauses.

Six entries on clauses: the ones that stand alone, the ones that cannot, and the words that join or subordinate them.

A clause that can stand alone.

CMP 0031 Independent Clauses

An independent clause, also called a main clause, has a subject and a predicate and can stand alone as a sentence. "The bus was late" is an independent clause; it makes complete sense by itself. Two independent clauses cannot be joined by a comma alone; that error, the comma splice, is covered in unit three.

A clause that cannot.

CMP 0032 Dependent Clauses

A dependent clause, also called a subordinate clause, has a subject and a verb but cannot stand alone. "Because the bus was late" has a subject and a verb, yet it leaves the reader waiting for the main point. A dependent clause written as a sentence by itself is a fragment, one of the commonest errors in drafts.

Words that make a clause depend.

CMP 0033 Subordinating Conjunctions

A subordinating word, such as although, because, since, when, unless or while, turns a clause into a dependent clause. "The bus was late" stands alone; "although the bus was late" does not, because although makes it depend on another clause. Adding one of these words to a complete sentence can create a fragment, so check what follows it.

The seven joiners.

CMP 0034 Coordinating Conjunctions

The seven coordinating conjunctions are for, and, nor, but, or, yet and so, remembered as fanboys. They join words, phrases or clauses of equal importance; with a comma before them, they join two independent clauses. Starting a sentence with and or but is acceptable in many genres, but some instructors prefer to avoid it in formal papers.

Transitions that are not conjunctions.

CMP 0035 Conjunctive Adverbs

Transitional words such as however, therefore, meanwhile, consequently and furthermore link ideas but are not conjunctions. Between two independent clauses they need a semicolon before them and usually a comma after: "Sales fell; however, the store survived." A comma alone before however creates a comma splice, an error the exam tests often.

Clauses that describe.

CMP 0036 Relative Pronouns and Clauses

The relative pronouns who, whom, whose, which and that begin dependent clauses that describe a noun. In "The student who won the prize thanked her teacher," the clause who won the prize describes the student. A relative clause written alone, such as "Which made the decision harder," is a fragment.

Four entries on the four structures, each defined by how many clauses it has and what kind.

One main idea.

CMP 0037 Simple Sentences

A simple sentence has one independent clause and expresses one main idea. It can be short, "The plan failed," or long, "After months of careful planning by the committee, the plan failed in its first week," because phrases do not add clauses. Simple describes structure, not length or difficulty.

Two equal clauses.

CMP 0038 Compound Sentences

A compound sentence joins two or more independent clauses of equal importance. Join them with a comma and a coordinating conjunction, with a semicolon, or with a semicolon and a transitional word such as however. Compounding works when the ideas really are equal; it flattens ideas when one should depend on the other.

One main clause and more.

CMP 0039 Complex Sentences

A complex sentence has one independent clause and one or more dependent clauses. In "Because the bus was late, the meeting started without us," the main idea sits in the independent clause, and the dependent clause gives the reason. Put the idea you want readers to remember in the independent clause.

Both kinds at once.

CMP 0040 Compound-Complex Sentences

A compound-complex sentence has two or more independent clauses and at least one dependent clause. "Although the forecast was clear, the storm arrived early, and the game was cancelled" has one dependent clause and two independent ones. This structure can carry complicated relationships, but it can also bury them; check that readers can still find the main point.

Five entries on using structure in revision: finding the core, sentence length, structure as meaning, a step-by-step diagnosis, and a worked example. The opening idea is paid off at the last.

Stripping a sentence down.

CMP 0041 Finding the Core of a Long Sentence

Most sentence errors become visible once a long sentence is stripped to its core subject and verb. Cross out prepositional phrases, set aside dependent clauses and set aside descriptive material between commas. What remains is the core: find the verb and ask who or what performs it. In the entry's example, a long sentence about a list of required books strips down to "The list are posted," which shows that list needs is. Do not trust the noun closest to the verb; agreement depends on the true subject.

Too short, or never ending.

CMP 0042 Short Sentences and Labyrinthine Ones

Very short sentences in a row read as choppy, and a sentence that seems never to end, called labyrinthine, is hard to follow. Writers sometimes use either on purpose, for action or for events running together, but in academic writing they more often suggest error. Aim for a balance of lengths; reading aloud reveals both problems.

Choosing how ideas relate.

CMP 0043 Why Structure Matters in Revision

Choosing a sentence structure is choosing how ideas relate: equal, dependent or one after another. "The rain stopped, and we left" treats the ideas as equal; "When the rain stopped, we left" makes one the condition of the other. Revision questions often turn on this choice, so ask which relationship the writer means before picking a version.

A diagnosis in order.

CMP 0044 Diagnosing a Sentence Step by Step

Diagnosing a sentence means counting its clauses and checking how they are joined. Find every verb with its own subject; each pair is a clause. Decide which clauses can stand alone. Check the joints between independent clauses: a comma with a coordinating conjunction, a semicolon or a period are correct; a comma alone or nothing at all is an error. Check that every dependent clause is attached. Then name the structure. These steps catch errors that reading by ear misses, where the rhythm sounds fine but a comma is quietly joining two sentences.

The same facts, four ways.

CMP 0045 One Sentence, Four Structures

A worked example, constructed for this course, pays off the opening idea. Three facts: the library extended its hours, students had asked for more study space, and exam week was approaching. As three simple sentences, every fact gets equal weight and the passage reads as choppy. As a compound sentence, the facts are joined as equals, so the cause is only implied. As a complex sentence beginning with because, the request is marked as the reason. As a compound-complex sentence, all three fit, with the cause subordinated. None of these structures is correct in itself. A revision choice is right when its structure matches the relationship the writer means, so read the surrounding sentences to see which idea the paragraph stresses.

Look at what you can now do. You can name a sentence's subject and predicate, its objects and complements, and the phrases that fill it out. You can tell an independent clause from a dependent one, and name the conjunctions, transitional words and relative pronouns that join or subordinate them. You can classify the four sentence structures by their clauses. And you can strip a long sentence to its core, diagnose its joints, and choose the structure that matches what the writer means. Unit Three applies this to the boundaries between sentences: fragments, run-ons and comma splices.