Write Clearly: Grammar

In this guide, bold font and parentheses are used to draw attention to subjects, verbs, conjunctions, conjunctive adverbs, commas, colons, semi-colons, and periods. Screen Reader Users: Please set your program’s punctuation level to 'most' or 'all' in order to hear the content in parentheses.

A sentence is a group of words that express a complete thought. In English, a simple sentence is made up of a subject + a verb + possibly an object. This sentence structure is sometimes represented as SVO.

To understand sentences, you must first understand clauses, which make up sentences. A clause is defined as a group of words containing both a subject and a verb. Clauses can be independent or dependent (also known as subordinate).

• An independent clause contains both a subject and a verb and can stand alone as a sentence.
  • Example: The dog (subject) ran (verb) after the ball.
•  A dependent clause contains both a subject and a verb, but cannot stand alone as a sentence.
  • Example: ... because (subordinating conjunction) he loved to play fetch
• Dependent clauses are introduced by subordinating conjunctions such as because, that, what, while, who, which, although, if, etc.
  • Example: The dog ran after the ball because (subordinating conjunction) he loved to play fetch.

There are three kinds of sentences:

Simple

A simple sentence consists of one main (or independent) clause. To be complete, a simple sentence must have at least one subject and one verb.

Example: The man (subject) went (verb) to the store.

Compound

A compound sentence has at least two main (or independent) clauses, connected by coordinating conjunctions (for, and, nor, but, or, yet, so). Each clause has its own subject(s) and verb(s).

Example: The man went to the store, and the sales clerk sold him some milk.

• First independent clause: The man went to the store
• Coordinating conjunction: and
• Second independent clause: the sales clerk sold him some milk
• The second clause should be separated from the first by a comma in front of the coordinating conjunction.

Complex

A complex sentence has at least one main (or independent) clause and at least one dependent (or subordinate) clause.

Example: When an atom is split, it releases neutrons.

• Dependent clause: When an atom is split
• Independent clause: it releases neutrons

See more information on types of dependent clauses in this LibGuide: Using Dependent Clauses Effectively. 

A sentence fragment is an incomplete sentence. It usually lacks either a subject or a verb, or both, or contains only a dependent clause.  
Examples: 

• For example, three dogs and a goat.
  • Problem: no verb--what did the animals do?
• Studying too hard on weekends.
  • Problem: no subject--who was studying?
•  Because I couldn’t find my shoes.
  • Problem: contains a subject and verb, but it is a dependent clause. Because you couldn’t find your shoes what?

A succession of short sentences, without transitions to link them to each other, results in choppy sentences. To correct, join the sentences as clauses using appropriate transitions and conjunctions. 

Example: 

• Incorrect: Our results were inconsistent. The program obviously contains an error. We need to talk to Paul Davis. We will ask him to review the program. 
• Correct: We will ask Paul Davis to review the program for errors because it produced inconsistent results. 

A run-on sentence is one in which two or more independent clauses (or complete sentences) are joined incorrectly by missing punctuation, a connecting word, or both. The two types of run-on sentences are fused sentences and comma splice errors.

Remember that the length of a sentence does not determine whether it is a run-on sentence: a sentence that is correctly punctuated and correctly joined can be extremely long.

Types of Run-On Sentences

There are two types of run-on sentences;

Type 1 - Fused sentence 

In a fused sentence, independent clauses follow each other in a sentence with no punctuation.

Example:

• Incorrect: The experiment failed it had been left unobserved for too long.

Type 2 - Comma splice

A comma splice error refers to the error of placing only a comma between two independent clauses, without a connecting word (such as and, but, or because).

Example:

• Incorrect: The experiment failed, it had been left unobserved for too long.

A comma splice also occurs when commas are used before conjunctive adverbs (therefore, however, nevertheless, moreover, etc.) connecting two independent clauses.

Examples:

• Incorrect: The experiment had been left unobserved for too long, (comma) therefore (conjunctive adverb), (comma) it failed.
• Correct: The experiment had been left unobserved for too long; (semi-colon) therefore (conjunctive adverb), (comma) it failed.
• Incorrect: He wasn’t prepared to defend a client who was guilty, (comma) however (conjunctive adverb), (comma) he could be persuaded to accept a bribe.
• Correct: He wasn’t prepared to defend a client who was guilty; (semi-colon) however (conjunctive adverb), (comma) he could be persuaded to accept a bribe.

Note: When the conjunctive adverb is within the clause rather than at the beginning, place it between commas.

Example:

• Correct: He wasn’t prepared to defend a client who was guilty; (semi-colon) he could be persuaded, (comma) however (conjunctive adverb), (comma) to accept a bribe.

How to correct a fused sentence or a comma splice error:

To correct a fused sentence or a comma splice error, you can use either a period, semi-colon, colon, comma plus coordinating conjunction, or subordinating conjunction.

Examples (correct):

• The experiment failed. (period) It had been left unobserved for too long.
• The experiment failed; (semi-colon) it had been left unobserved for too long.
• The experiment failed: (colon) it had been left unobserved for too long.
• The experiment had been left unobserved for too long, (comma) so (coordinating conjunction) it failed.
• The experiment failed because (subordinating conjunction) it had been left unobserved for too long.

A loose sentence results when the main (independent) clause is followed by many phrases and clauses that add information but in no particular order.
Example:;

• We got the contract, and we must be ready by June 1 with the necessary personnel and equipment to get the job done, so with this in mind a staff meeting, which all group managers are expected to attend, is scheduled for February 12.
  • NOTE: Writing the previous sentence as several sentences would be more effective.

Inappropriate coordination results if you use “and” as a connective when other conjunctions would convey a more precise meaning.

Example:

• John had a weight problem, and (coordinating conjunction) he dropped out of school.
  • Problem: what is the most accurate connection: John had a weight problem so he dropped out of school or because he dropped out of school? 

Excessive coordination results when several clauses are joined by coordinating conjunctions. If you are trying to correct choppy sentences by joining them, be careful that you do not end up with excessive coordination instead.

Example:

• Roses are a popular flower, and they are difficult to grow, so many people choose to purchase them as cut flowers instead, but that can be expensive.

Excessive subordination results when a number of simple sentences are joined together with subordinating conjunctions (because, that, which, after, if, etc.). This error can cause confusion for the reader because it is unclear how the parts of the sentence are related. If you are trying to correct choppy sentences by joining them, be careful that you do not end up with excessive subordination instead.;

Example:

• Incorrect: Doug thought that he was prepared but he failed the examination which meant that he had to repeat the course before he could graduate which he didn’t want to do because it would conflict with his summer job.
• Correct: Doug thought that he was prepared, but he failed the examination. Therefore, he would have to repeat the course before he could graduate. He did not want to do that because it would conflict with his summer job.

Parts of a sentence which are in sequence should all follow the same grammatical or structural principle.

Examples:

• Incorrect: I like to swim, to sail, and rowing.
• Correct: I like to swim, to sail, and to row.
• Correct: I like swimming, sailing, and rowing.
• Incorrect: This report is an overview of the processes involved, problems that we encountered, and how they were solved.
• Correct: This report is an overview of the processes involved, the problems encountered, and the solutions implemented.