Explain the function of phrases and clauses, choose among simple, compound, complex and compound-complex sentences, and correct misplaced and dangling modifiers

Learning goal: Demonstrate command of the conventions of standard English grammar and usage when writing or speaking. Explain the function of phrases and clauses in general and their function in specific sentences; choose among simple, compound, complex and compound-complex sentences to signal differing relationships among ideas; and place phrases and clauses within a sentence, recognizing and correcting misplaced and dangling modifiers. Every example below is labeled, and the corrected version of every faulty sentence is given.

Phrases: a group of words without a subject-verb pair. A phrase is a group of words that works as a single unit in a sentence but does not contain both a subject and a verb that agrees with it. Because it has no subject-verb pair, a phrase can never stand alone as a sentence. The main kinds, each with a labeled example built around one invented footbridge, are these. A noun phrase names something: "the old footbridge." A verb phrase is the verb with its helpers: "has been repaired." A prepositional phrase begins with a preposition and ends with its object: "across the creek." An appositive phrase renames a noun beside it: "Ms. Lindqvist, a retired engineer, inspected it." A participial phrase begins with a participle and describes a noun: "Standing on the bank, she photographed the railing." A gerund phrase is an -ing form used as a noun: "Crossing the footbridge takes two minutes." An infinitive phrase is to plus a verb: "The council voted to repair the railing."

Function in general and in a specific sentence (L.7.1a). In general, a verb phrase does the verb's work in its clause (it is the verb of the predicate), and the other kinds of phrase function as one of three parts of speech: as a noun (a subject, object or complement), as an adjective (describing a noun) or as an adverb (telling how, when, where, why or to what extent). Gerund phrases and infinitive phrases often act as nouns; participial phrases act as adjectives; appositive phrases are noun phrases that rename the noun beside them, a job close to an adjective's; prepositional phrases act as adjectives or adverbs, and which one depends on the specific sentence. That last point is the heart of the standard: you must be able to say what a phrase does in the sentence in front of you, not just what its kind usually does. Compare "The footbridge across the creek is closed" with "The students walked across the creek." The same prepositional phrase, "across the creek," modifies the noun footbridge in the first sentence, telling which footbridge, so there it functions as an adjective. In the second it modifies the verb walked, telling where, so there it functions as an adverb. Likewise "to repair the railing" is a noun, the object of voted, in "The council voted to repair the railing," but an adverb telling why in "The crew arrived to repair the railing."

Clauses: a group of words with a subject and a verb. A clause contains a subject and a finite verb, a verb that agrees with its subject and shows tense. (An -ing or -ed form without a helper is not finite, which is why "his hands trembling" in "His hands trembling, he unlocked the door" is a phrase and not a clause.) An independent clause expresses a complete thought and can stand alone as a sentence: "The footbridge closed in March." A dependent clause also has a subject and a verb but begins with a word that makes it depend on something else, a subordinating conjunction such as because, although, when, if, since, unless, or a relative pronoun such as who, which, that: "because the footbridge closed in March." Read alone, that leaves the listener waiting; it must attach to an independent clause. Dependent clauses function in general as adverbs (telling why, when, under what condition), as adjectives (describing a noun: "the railing that rusted through") or as nouns ("The engineer explained why the railing failed," where the clause is the object of explained). In a specific sentence, name the function: in "Although the bridge is closed, the trail is open," the clause "although the bridge is closed" functions as an adverb of concession attached to the main clause.

Four sentence types and the relationships they signal (L.7.1b). A simple sentence has one independent clause and no dependent clause; it may still have a compound subject or verb and any number of phrases. Labeled simple: "The footbridge and the trail closed in March." A compound sentence has two or more independent clauses joined by a comma and a coordinating conjunction (for, and, nor, but, or, yet, so) or by a semicolon. Labeled compound: "The footbridge closed in March, and the detour added ten minutes to every walk." A complex sentence has one independent clause and at least one dependent clause. Labeled complex: "Because the footbridge closed in March, the detour added ten minutes to every walk." A compound-complex sentence has at least two independent clauses and at least one dependent clause. Labeled compound-complex: "Because the footbridge closed in March, the detour added ten minutes to every walk, and the morning buses ran late."

Choosing among them is a matter of meaning, not decoration. Coordination, in a compound sentence, presents two ideas as equal partners: the closure and the detour, side by side. Subordination, in a complex sentence, ranks them: because makes the closure the cause and the detour the result, and puts the result in the independent clause where the weight falls. Although signals concession, when signals time, if signals condition. A writer who wants the reader to feel the cause chooses complex; a writer listing two facts of equal weight chooses compound; a writer who wants one crisp fact chooses simple. The misconception is that longer sentences are more mature. A paragraph of nothing but compound-complex sentences tends to bury its relationships under equal-looking length; a paragraph of nothing but simple sentences leaves the relationships to vocabulary and transitions alone ("As a result, ..."), which can work but often reads as a list. Command means choosing the type whose structure matches the relationship among the ideas.

Placing phrases and clauses: misplaced and dangling modifiers (L.7.1c). A modifier is a word, phrase or clause that describes another part of the sentence, and English readers attach a modifier to the nearest word it could sensibly describe. A misplaced modifier sits next to the wrong word, so the sentence says something the writer did not mean. Misplaced: "The custodian found a phone walking down the hall." As placed, the participial phrase attaches to phone, so the phone was walking. Corrected: "Walking down the hall, the custodian found a phone." Single words misplace too. Misplaced: "She almost repaired every railing on the bridge." Read strictly, that says she came close to repairing but did not; many readers will guess the intended meaning, but the placement leaves it open. Corrected, if the meaning is that most railings were repaired: "She repaired almost every railing on the bridge." A dangling modifier describes a word that is not in the sentence at all, usually because the writer left out the doer. Dangling: "Standing on the roof, the courtyard looked small." Nothing in the sentence was standing on the roof; the courtyard cannot stand. Corrected by supplying the doer: "Standing on the roof, we thought the courtyard looked small," or "When we stood on the roof, the courtyard looked small." The test for a participial phrase at the start of a sentence is simple: the subject of the main clause, which normally comes immediately after the comma, must be the one doing the action in the phrase. If the right noun appears elsewhere in the sentence, the modifier is misplaced and can be moved beside it; if the right noun is absent, or appears only inside a phrase such as "by the group," the modifier dangles, and the fix is to rebuild the sentence with the doer as its subject.

Moving a phrase or clause: variety, emphasis and meaning. Some phrases and clauses can move without becoming misplaced, and where they go still matters. Moving one can do three different things. It can add variety: a paragraph in which every sentence opens with its subject ("The footbridge closed. The detour added ten minutes. The buses ran late.") reads like a list, and opening one sentence with a phrase or clause ("In March, the footbridge closed.") changes the rhythm without changing the facts. It can emphasize a particular relationship among ideas: readers tend to give the most weight to the end of a sentence, so the idea placed last is the one that lands. "Because the footbridge closed in March, the detour added ten minutes to every walk" ends on the detour, the effect. "The detour added ten minutes to every walk because the footbridge closed in March" ends on the closure, so it answers the question "why?" and emphasizes the cause. Both are correct; they suit different paragraphs. Notice the comma: a dependent clause that opens a sentence is usually followed by a comma, while one that ends it usually is not. The exception is a closing clause of contrast or concession, introduced by although, even though or whereas, which usually keeps its comma, as the second sentence of Worked example 4 does. And moving a phrase or clause can alter the meaning of a sentence, as the modifier examples above show: moving "almost" or "only" changes what the sentence claims. The test for any move is to ask which of the three it does. If the meaning stays the same, the move is a choice about variety or emphasis; if the meaning changes, the move is either a correction or a new error.

A worked model in prose. Take the draft sentence "After reading the estimate, the staircase seemed expensive to the council, which nobody had priced." Two faults. "After reading the estimate" dangles: the staircase did not read anything. And "which nobody had priced" sits next to council, so it seems the council was unpriced, when the writer meant the staircase. Rebuild it: "After reading the estimate, the council thought the staircase, which nobody had priced, seemed expensive." Now the council reads, and the adjective clause sits beside staircase. Then choose the sentence type deliberately. Written as one complex sentence, it makes the reading background and the judgment the point. If the writer instead wants two equal facts, compound: "The council read the estimate, and the unpriced staircase worried its members." Both are correct; they signal different relationships, and that is the choice L.7.1b asks you to make.

Worked example 1 — naming the function of the same phrase in two sentences. Sentence A: "The lesson on pollination needs flowering plants." Sentence B: "The class worked on pollination for a week." In A, "on pollination" tells which lesson, so it modifies the noun lesson and functions as an adjective. In B, "on pollination" tells what the class worked on, modifying the verb worked, so it functions as an adverb. In general, a prepositional phrase can do either; in a specific sentence, find the word it attaches to and name the function from that.

Worked example 2 — rewriting one pair of ideas as four sentence types and saying what each signals. Ideas: the load check takes six weeks; the roof garden cannot begin before May. Simple (one idea only, one independent clause): "The load check takes six weeks." Compound (two equal facts): "The load check takes six weeks, so the roof garden cannot begin before May." Complex (cause ranked under result): "Because the load check takes six weeks, the roof garden cannot begin before May." Compound-complex (a cause, a result, and a second equal fact): "Because the load check takes six weeks, the roof garden cannot begin before May, and the council has recommended the courtyard." The compound version with so does show cause, but as a link between equals; the complex version subordinates the cause and puts the weight on the delayed garden.

Worked example 3 — diagnosing and correcting three modifiers. Draft 1: "Covered in rust, the engineer condemned the railing." The participial phrase attaches to engineer, so the engineer is rusty: misplaced. Corrected: "The engineer condemned the railing, which was covered in rust." Draft 2: "To reach the roof, a staircase is required." Nothing in the sentence is reaching the roof; the infinitive phrase dangles. Corrected: "To reach the roof, students will need a staircase." Draft 3: "The council only discussed the courtyard on Tuesday." As placed, only sits beside discussed, so the sentence can be read as saying they did nothing but discuss. If the meaning is that Tuesday was the sole day, corrected: "The council discussed the courtyard only on Tuesday." Each correction moves the modifier next to the word it describes or supplies the missing doer.

Worked example 4 — one clause in three positions, then a move that alters meaning. Opening: "Although the survey favored the roof, the council chose the courtyard." The sentence ends on the decision, so the decision is what lands. Closing: "The council chose the courtyard, although the survey favored the roof." The sentence now ends on the concession, which emphasizes the tension between the survey and the decision; a writer about to explain that tension would choose this order. Interrupting: "The council, although the survey favored the roof, chose the courtyard." The clause now sits between subject and verb and makes the reader wait for the decision, which adds variety to a paragraph of plain openings. In all three the meaning is the same; the relationship emphasized changes. Now a move that alters meaning: "On Tuesday, the council said it would discuss the courtyard" means the council spoke on Tuesday. "The council said it would discuss the courtyard on Tuesday" most naturally means the discussion will happen on Tuesday. Moving the phrase "on Tuesday" changed what the sentence claims, so the writer must place it next to the part it is meant to modify.

Sentence anatomy chart: Take one paragraph of your own recent writing, at least six sentences. For each sentence, label its type (simple, compound, complex or compound-complex), underline every dependent clause and bracket every phrase of at least three words, and beside each bracketed phrase write its function in that sentence: noun, adjective or adverb, or verb for a verb phrase. Then rewrite two sentences as a different type and state what relationship among ideas the change signals. A strong chart labels every sentence correctly and names a function for every phrase, not just its kind.

Independent performance: Write a one-page explanation of a decision, real or invented, that has at least two causes and one objection. Use all four sentence types at least once, and beside each of four sentences of your choosing, write a margin note naming the type and the relationship its structure signals (cause, concession, equal facts, time, condition). Then exchange papers and hunt for misplaced or dangling modifiers in your partner's page; mark each one, state whether it is misplaced or dangling and why, and write a correction. Success criteria: all four types are present and correctly labeled; every margin note names a real relationship signaled by the structure; every modifier in the final draft sits next to the word it describes, and every opening participial or infinitive phrase is followed by its doer.

Placement item, with a model answer: (1) Move the dependent clause in "Because the load check takes six weeks, the roof garden cannot begin before May" to the end of the sentence, and say what the move emphasizes. (2) Explain whether moving "only" in "The council only recommends the courtyard this year" to "The council recommends the courtyard only this year" is a choice of emphasis or a change of meaning. Model answer: (1) "The roof garden cannot begin before May because the load check takes six weeks." The meaning is unchanged, but the sentence now ends on the cause, so it emphasizes why the garden is delayed rather than the delay itself; the comma is dropped because a closing clause of cause, like this because clause, usually takes none (a closing although or whereas clause would keep it). (2) It is a change of meaning. In the first version, "only" sits beside "recommends," so the sentence can be read as saying the council merely recommends and does nothing more. In the second, "only" limits "this year," saying the recommendation holds for this year and not beyond. The move is correct only if the second meaning is the one the writer intends.