In order to understand errors in sentence construction, we need to have a grasp of the various patterns of correct sentences.
Basic Sentence Patterns:
A sentence is conventionally said to consist of two parts: the subject (the person or thing performing the action) and the predicate (what is asserted or said of that person or thing):
The lady in red attended the concert last night.
As a working rule, the meaning of a sentence should be able to stand independently. The simplest pattern for a sentence is subject + verb:
A reader can understand the meaning of this, though this meaning might be modified by further knowledge of the context in which the sentence occurs. Note that the verb here is intransitive, i.e. it needs no object.
The next sentence pattern involves a transitive verb, i.e. a verb which takes an object. Hence this type of sentence comprises subject + verb + direct object:
The gladiators killed Caligula.
Subject verb direct object
Some verbs, such as “give,” “convey,” “report,” and “send,” take an indirect object as well as a direct object, giving us a further sentence pattern subject + verb + direct object + indirect object:
Varinia gave the book to me.
Subject verb direct indirect
Another type of sentence uses linking verbs, such as “seem,” “look,” “appear,” and “be.” Such verbs are followed by a subject complement, an adjective or noun which qualifies the subject:
Hasdrubal’s officers seemed angry.
Subject verb subject complement
Hasdrubal was Hannibal’s brother.
Subject verb subject complement
Similarly, an object complement qualifies the object, giving us the pattern subject + verb + direct object + object complement:
The soldiers hailed Vitellius Emperor.
Subject verb direct object object complement
Group (A): Sentence fragments, run-on sentences, comma splices:
(1) Sentence fragments:
A sentence fragment is an incomplete sentence, punctuated as if it were a sentence. Fragments arise in a number of circumstances:
(a) When the subject is missing:
And went to the store.
Correction: He went to the store.
(b) When the verb is missing:
She needed three things. Paper, a pencil, and bootlaces.
Correction: She needed three things: paper, a pencil, and bootlaces.
With the revised punctuation, the verb “needed” refers to paper, a pencil, and bootlaces.
(c) When both subject and verb are missing:
Demanding to see the Manager.
Correction: He demanded to see the manager.
(d) When the intended sentence is a dependent clause:
He was executed. Because he murdered twelve people.
Correction: He was executed because he murdered twelve people.
She was a great artist. Who was very unconventional.
Correction: She was a great artist, who was very unconventional.
An independent clause is a group of words which includes a subject and a verb, and can stand alone as a complete sentence:
Marcellus liked computers.
A dependent or subordinate clause contains a subject and a verb but it cannot stand alone:
Although Marcellus liked computers.
A dependent clause begins with a word such as “because,” “since,” “who,” “which,” “that,” “if,” “whether,” “when,” “whenever,” “until,” “before,” “after,” and “although.” These are called subordinating words because they subordinate the idea in the dependent clause to the idea in the main clause:
Although Marcellus liked computers, he had no computer.
Subordinate clause main clause
Dependent clause independent clause
The main idea conveyed by this sentence is that Marcellus had no computer; that he liked computers is the secondary or subordinate idea. It can be seen, in the examples above, that this type of fragment is corrected by attaching the dependent clause to an independent clause. Alternatively, we could delete the subordinating word. In the example above, we could delete “although,” so that the sentence would read: Marcellus likes computers.
As a general working rule, fragments don’t make sense on their own. A good test for most types of sentence fragments is to see whether you can add a question-tag to them:
Sentence: Pervigilianus baked the cookies.
Question-tag: Pervigilianus baked the cookies, didn’t he?
Fragment: Although Pervigilianus baked the cookies.
We are unable to attach a question tag to the fragment.
(2) Run-on sentences and comma splices:
A run-on (fused) sentence consists of two independent clauses which are run together with no punctuation between them:
Lavinia arrived early for her wedding the groom came late.
Independent clause independent clause
A comma splice occurs when two independent clauses have only a comma between them:
Beatrice raised her voice, she was angry with Dante.
Independent clause independent clause
There are a number of ways in which we can correct run-on sentences and comma splices:
(a) punctuate the clauses as two separate sentences by placing a period or semi-colon between them:
Beatrice raised her voice; she was angry with Dante.
(b) separate the two clauses with a co-ordinating conjunction and a comma:
Lavinia arrived early for her wedding, but the groom came late.
(c) subordinate one clause to the other, using a subordinating conjunction:
Although Lavinia arrived early for her wedding, the groom came late.
(d) replace the verb in one clause with a participle:
Beatrice raised her voice, being angry with Dante.
Being angry with Dante, Beatrice raised her voice.
Errors: Group (B): Use of Pronouns:
(1) Indefinite pronouns: the following pronouns are grammatically singular in form:
each either neither
everyone everybody anyone anybody
someone somebody something
no one nobody nothing
Hence, if any of these pronouns is used as an antecedent, a singular pronoun must be used to refer to it, and a singular verb must be used with it:
Incorrect: Everyone picked up their books.
Each of us were amazed.
Neither of the books interest me.
Correct: Everyone picked up his/her book(s).
Each of us was amazed.
Neither of the books interests me.
However, it is often easier and less clumsy to cast the whole sentence in plural form:
They all picked up their books.
(2) Pronoun-antecedent reference: a pronoun refers to a noun or pronoun (the antecedent) that has been used earlier. It should be made clear just what this antecedent is; it’s also important to avoid using a pronoun without an antecedent:
Unclear: Although Jane trusted Sally, she failed to contact her.
Clear: Although Jane trusted Sally, Sally failed to contact her.
Unclear: During Augustus’ reign, they hailed him as a god.
Clear: During Augustus’ reign, the Roman people hailed him as a god.
(3) Pronoun-antecedent agreement: a pronoun should agree in number with its antecedent:
Incorrect: When a person is sixteen, they should be allowed to drive.
Correct: When a person is sixteen he or she should be allowed to drive.
Incorrect: If a student fails the course, they are allowed to retake it.
Correct: If a student fails the course, he or she is allowed to retake it.
Correct: If any students fail the course, they are allowed to retake it.
(4) Use of the pronoun “one”: if you use the impersonal pronoun “one” in a pronoun-antecedent construction, you must repeat it:
Incorrect: One goes home to be with their family and friends.
Incorrect: One goes home to be with his or her family and friends.
Correct: One goes home to be with one’s family and friends.
(5) Relative pronouns: the relative pronouns “who” and “whoever” are used for subjects in a sentence; “whom” and “whomever” are used for objects:
Incorrect: She was the girl who I saw in the library.
Correct: She was the girl whom I saw in the library.
In this sentence the subject of the verb “saw” is “I”; the girl is the object.
Incorrect: The King rewarded whomever helped him.
Correct: The King rewarded whoever helped him.
In this case, although whoever is the object of rewarded, it is the subject of the verb helped.
Errors: Group (C): Use of modifiers:
A modifier is a word or group of words that describes, qualifies (modifies) another word or group of words:
The legions, exhausted by their long march, rested.
Subject modifier verb
In this sentence, the phrase “exhausted by their long march” modifies or describes “the legions”. Below are a number of common errors in the use of modifiers.
(1) Misplaced modifiers: you need to make it clear to which word or group of words a modifier applies:
Incorrect: Travelling faster than sound, Victorinus heard the plane.
Correct: Victorinus heard the plane, travelling faster than sound.
It is not Victorinus but the plane to which travelling faster than sound applies. It is most annoying when people misplace their modifiers.
(2) Misplaced subordinate clauses: if a subordinate or dependent clause is used as a modifier, its reference to what it modifies needs to be clear:
Unclear: Fabius managed to entertain his child while he was bandaging his wound.
Clear: While he was bandaging his wound, Fabius managed to entertain his child.
It is Fabius, not his child, who is bandaging his wound.
(3) Dangling modifiers: a dangling modifier is a word or group of words which does not modify anything in the sentence:
Using his skill, the surgery was completed successfully.
The modifier “using his skill” does not refer to anything in the sentence. We can correct the sentence by introducing a subject:
Using his skill, he completed the surgery successfully.
The modifier now refers to the subject “he”. Alternatively, we could turn the modifier into a subordinate clause:
Because of the doctor’s skill, the surgery was completed successfully.
Just about the worst thing you can do with a modifier is to dangle it. So try to avoid such grammatological compromise.