All sentences must be grammatically correct. Make sure you proofread your work thoroughly to check for the following sentence level errors.
Sentence fragments
A sentence fragment is an incomplete sentence. Often, a sentence fragment is missing either a subject or verb.
✖Missing verb: The team of scientists the samples through the microscope.
✔With verb: The team of scientists examined the samples through the microscope.
✖Missing subject: When the report was delivered.
✔With subject: When the report was delivered, the committee debated the findings.
Fixing sentence fragments:
Make sure each sentence has both a subject and a verb.
Run-on sentences
A complete sentence with a subject and a verb is also called an independent clause. When two independent clauses are joined together incorrectly, this is called a run-on sentence. A run-on sentence has multiple subjects, each with its own verb.
✖Two independent clauses joined incorrectly: [independent clause 1] The Howard Coalition government, in 2001, wanted to prevent people seeking asylum arriving by boat [independent clause 2] this resulted in the government enacting what is known as the Pacific Solution.
Fixing run-on sentences:
The simplest way to fix run-on sentences is to add a full stop and capitalise the following word. The full stop should separate the first sentence from the second.
✔Two independent clasues joined correctly: The Howard Coalition government, in 2001, wanted to prevent people seeking asylum arriving by boat. This resulted in the government enacting what is known as the Pacific Solution.
You can also fix run-on sentences using coordinating conjunctions.
Subject-verb agreement
For a sentence to be grammatically correct, the subject and verb must “agree.” A common error is when the subject is either singular or plural and the verb does not agree. The below examples look at present tense verbs.
With third person singular subjects (he/she/ t), in the present tense, add “s” to the end of regular verbs.
✖Subject and verb don’t agree: A market rise because of investor optimism.
✔Subject and verb agree: A market rises because of investor optimism.
With third person plural subjects (they), in the present tense, do not add “s” to the end.
✖Subject and verb don’t agree: Doctors watches to see if any symptoms reoccur.
✔Subject and verb agree: Doctors watch to see if any symptoms reoccur.
Note that the “to be” verb is an example of an irregular verb. Irregular verbs do not obey the rules above.
With third person singular subjects in the present tense:
✔He/she/it: is
With third person plural subjects in the present tense:
✔They: are
For more information on subjects, verbs, irregular verbs, and subject-verb agreement see: English Grammar: The Basics.