Everyone should be able to write a polished, grammatically correct sentence, as writing skills reflect basic communication ability and knowledge. Common grammatical mistakes include sentence fragments, run-on sentences, subject-verb disagreement and nonparallel structure. Writers should be sure to correct any such mistakes before turning in their work.
A fragmented sentence is somehow incomplete; it either misses a subject or verb or the idea is not fully formed. Sentence fragments confuse readers and can cause them to question a writer’s authority on a subject. To prevent fragments, check sentences to ensure they have a noun, or subject, and an action word, or verb. In the example sentence, “Sally enjoys sailing,” "Sally" is the subject and "sailing" is the verb. Also watch for words that convey a thought that requires a follow-up. Examples of these types of words include "if," "when" and "because." For example, "Sally enjoys sailing when" is not a complete sentence, but "Sally enjoys sailing when her friends come along" is complete.
A run-on sentence is when two separate ideas are written into one sentence when they should be two different sentences. An example of a run-on sentence would be: "Jonah loves ice cream it is smooth and sweet." In this sentence, two different ideas are present: Jonah loves ice cream, and ice cream is smooth and sweet. The writer could use a semicolon after the word "cream" to create a fluid, grammatically correct sentence. Or the two ideas could be split into two separate sentences. Placing a comma between the two ideas will not work; this is called “comma splicing” and is not an acceptable fix for a run-on sentence.
Lack of Subject-Verb Agreement
In simple terms, a lack of subject-verb agreement simply means that the noun and verb do not match; both must be singular or plural. The following sentence illustrates a lack of subject-verb agreement: “The employees is mad at the boss.” In this sentence, the noun is plural, while the verb (in this case, “is”) is singular. The correct verb should be “are.” When writing, verify that all nouns and verbs are matched.
Improper Parallel Structure
Parallel structure refers to how different parts of a sentence correlate with each other; essentially each phrase or description should be in the same form. In this sentence, the parallel structure is missing: “Tony is a dedicated employee and smart.” In this sentence, the adjectives “dedicated” and “smart” are not in the same form. A correct example would be: Tony is a dedicated worker and smarter than most.