13.1 Parts of Speech and Sentence Structure

Parts of Speech and Their Functions

Nouns, Pronouns, and Their Functions

Nouns name a person (teacher), place (school), thing (book), or idea (freedom). In a sentence, nouns can serve several roles:

• Subject: The noun performing the action (The teacher explained the lesson.)
• Direct object: The noun receiving the action (She read the book.)
• Indirect object: The noun that receives the direct object (He gave the student a pencil.)
• Object of a preposition: The noun following a preposition (She sat on the chair.)
• Subject complement: The noun that renames or describes the subject after a linking verb (Mr. Davis is a teacher.)

Pronouns replace nouns so you don't have to repeat the same word over and over. Words like she, it, they, and whom are all pronouns, and they can fill the same roles as nouns: subject, direct object, indirect object, object of a preposition, or subject complement.

Verbs, Adjectives, and Adverbs

Verbs express either an action (run, analyze) or a state of being (is, were). Two things to know about verbs right away:

• They must agree with their subject in number and person (She runs vs. They run).
• They can be transitive (taking a direct object: She threw the ball) or intransitive (no direct object: He slept).

Adjectives modify nouns and pronouns. They can appear directly before the word they describe (the blue sky) or after a linking verb as a predicate adjective (The sky is blue).

Adverbs modify verbs, adjectives, or other adverbs. They answer questions like how? (quickly), when? (yesterday), where? (here), how much? (very), and how often? (frequently).

Prepositions, Conjunctions, and Interjections

Prepositions show the relationship between a noun or pronoun and another word in the sentence. Words like on, under, by, and between are prepositions. They're always followed by a noun or pronoun (called the object of the preposition), forming a prepositional phrase: on the table, by the river.

Conjunctions connect words, phrases, or clauses. There are two main types:

• Coordinating conjunctions (and, but, or, nor, for, so, yet) join elements of equal grammatical importance.
• Subordinating conjunctions (because, although, when, if) introduce dependent clauses and create an unequal relationship between clauses.

Interjections express strong emotion or surprise (wow, ouch, hey). They're often followed by an exclamation point and can stand alone.

Sentence Structure Analysis

Simple and Compound Sentences

A simple sentence has one independent clause: a subject, a predicate, and a complete thought. That's it.

A compound sentence joins two or more independent clauses. Each clause could stand on its own as a sentence. You can connect them three ways:

• With a comma + coordinating conjunction: The cat sat on the mat, and the dog slept by the fire.
• With a semicolon: The cat sat on the mat; the dog slept by the fire.
• With a semicolon + conjunctive adverb: The cat sat on the mat; however, the dog slept by the fire.

Complex and Compound-Complex Sentences

A complex sentence has one independent clause and at least one dependent clause. The dependent clause can't stand alone and is introduced by a subordinating conjunction (because, although) or a relative pronoun (who, which, that).

Here, which was tired is the dependent clause. Remove it, and the independent clause still works fine.

A compound-complex sentence combines the features of both: two or more independent clauses plus at least one dependent clause.

This has two independent clauses joined by and, with the dependent clause which was also tired embedded in the second one.

Sentence Construction

Subject-Verb Agreement and Verb Tense Consistency

Subject-verb agreement means your subject and verb must match in number and person. Singular subjects take singular verbs; plural subjects take plural verbs.

• The student studies every night. (singular)
• The students study every night. (plural)

Verb tense consistency means you should stick with the same tense throughout a sentence or paragraph unless there's a real reason to shift. Compare:

• Consistent: She walked to the store and bought milk.
• Inconsistent: She walked to the store and buys milk.

That second version jumps from past to present tense for no reason, which confuses the reader about when things happened.

Modifier Placement and Parallel Structure

Place modifiers as close as possible to the word they describe. When modifiers drift too far from their target, sentences get confusing or unintentionally funny.

• Clear: She found a gold necklace in the drawer.
• Misplaced: She found a necklace in the drawer made of gold. (Was the drawer made of gold?)

Parallel structure means keeping items in a list or comparison in the same grammatical form. This makes your writing smoother and easier to follow.

• Parallel: She likes running, swimming, and cycling. (all gerunds)
• Not parallel: She likes running, to swim, and cycling. (mixed forms)

Consistency in Point of View, Voice, and Mood

Avoid unnecessary shifts in point of view (first, second, third person), voice (active vs. passive), or mood (indicative, imperative, subjunctive) within a sentence or paragraph.

• Inconsistent point of view: I went to the store, and you bought milk. (shifts from first to second person with no reason)
• Consistent point of view: I went to the store, and I bought milk.

Note that choosing active or passive voice is fine on its own. The problem is shifting between them within the same passage without purpose. Pick one and stick with it.

• Active: The dog chased the ball.
• Passive: The ball was chased by the dog.

Both are grammatically correct, but active voice is usually stronger and more direct.

Sentence Fragments vs. Run-On Sentences

Identifying and Correcting Sentence Fragments

A sentence fragment is an incomplete sentence. It's missing a subject, a predicate, or both, and it can't stand alone as a complete thought. Two common types:

• Dependent clause standing alone: Because he was tired. (This has a subject and verb, but the word because makes it dependent on another clause.)
• Phrase lacking a subject and/or predicate: Running down the street. (Who is running? There's no subject, and running alone isn't a complete predicate.)

To fix a fragment, either add what's missing or attach it to a nearby sentence:

1. Because he was tired. → He went to bed because he was tired.
2. Running down the street. → She was running down the street.

Recognizing and Fixing Run-On Sentences

A run-on sentence crams two or more independent clauses together without proper punctuation or conjunctions. There are two types:

• Fused sentence: Two clauses with nothing between them. He was tired he went to bed.
• Comma splice: Two clauses joined by only a comma, with no conjunction. He was tired, he went to bed.

Three ways to fix a run-on:

1. Period: Split them into two sentences. He was tired. He went to bed.
2. Semicolon: Connect closely related clauses. He was tired; he went to bed.
3. Comma + coordinating conjunction: He was tired, so he went to bed.