When a writer logically links two ideas by using parallel grammatical forms within a sentence, we call it parallelism. Parallelism is a great way to make connections between ideas and claims and so to advance an argument; parallelism is also a terrific device for summarizing and outlining to help keep your readers on track.

I. Using coordinating conjunctions to link parallel words, phrases and clauses: coordinating conjunctions (and, but, for, or, nor, so, yet) can join a pair or series to create compound subjects, verbs, objects, modifiers, and clauses.

• Parallel words: 
  NO: The councilman was a pragmatist but fixated on the bottom line.
  YES: The councilman was pragmatic but budget-conscious.
  NO: Goffman's mind was active and various ideas at once could be held.
  (The word active is an adjective, but its parallel partner is a whole noun phrase. We need to revise to make the noun phrase into an adjective to establish parallelism.)
  YES: Goffman's mind was active and varied.
  Parallel nouns: Music and logic are two required courses in the General Ed program.
  Parallel adjectives: In order to graduate, students must demonstrate musical and logical competence.
• Parallel phrases: 
  NO: Kinneavy excelled at clarifying complex relationships and used mapping techniques to visualize those relationships.
  (The first parallel element starts "...at clarifying" but the second, after the "and", starts with "used." We need to make the second element match or parallel the first.)
  YES: Kinneavy excelled at clarifying complex relationships and using mapping techniques to visualize those relationships.
  NO: Low numbers of majors and seeking a new chairman has put the Leisure Theory Department into jeopardy. 
  (The first element is a noun phrase ["Low numbers of majors"], while the second is a gerund (-ing) phrase ["seeking a new chairman"]. We to change the gerund into a noun phrase.)
  YES: Low numbers of majors and the search for a new chairman have put the Leisure Theory Department into jeopardy.
• Parallel clauses: (A clause, remember, has a subject and predicate. Clauses can be independent--they can stand alone as full sentences, or they can be dependent, which means their meaning is dependent on other sentence elements.)
  NO: Before the storm's end but after the worst was over, the captain radioed for help.
  ("Before the storm's end" uses a possessive structure; "after the worst was over" is a full clause; we have to make them parallel structures.)
  YES: Before the storm had ended but after the worst was over, the captain radioed for help.
  NO: By using word processors for all writing, by utilizing an email e-list, and frequently asking students to conduct discussions in a real-time chat environment, the class was computer-supported.
  (Parallelism demands a consistent use of connectives like [as in this example] the proposition "by." So we have to revise to make sure exactly the same structure is repeated.)
  YES: By using word processors for all writing, by utilizing an email e-list, and by asking students to conduct discussions in a real-time chat environment, the class was computer-supported.

II. Using correlative conjunctions to link parallel words, phrases and clauses: correlative conjunctions (either/or, neither/nor, both/and, not only/ but also) can join a pair or series to create compound subjects, verbs, objects, modifiers, and clauses.
 

• NO: After defeating Custer at Little Bighorn, Crazy Horse managed both to stay ahead of the army and escape. 
  ("to stay ahead of the army" is the first parallel element; the second is "escape." We have to make sure the form of the second element parallels the first.)
  YES: After defeating Custer at Little Bighorn, Crazy Horse managed both to stay ahead of the army and to escape.
  
  

• NO: The staff approved the first request for funding, not the second presenter who requested funds. 
  YES: The staff approved the first request for funding, not the second.
  NO: A newbie describes someone who is ignorant of an online environment, while a novice is being introduced generally for the first time.
  (The phrase "is being introduced..." is not parallel to the first element, "describes someone who...")
  YES: A newbie describes someone who is ignorant of an online environment, while a novice describes someone who is introduced for the first time.

• YES: On the one hand, artificial intelligence promises to automate and simplify some of the routine tasks that humans waste time performing. On the other hand, artificial intelligence threatens to replace human thinking and will to action.

A house divided against itself cannot stand. I believe this government cannot endure, permanently half slave and half free. I do not expect the Union to be dissolved. I do not expect the house to fall. But I do expect it will cease to be divided. It will become all one thing, or all the other.

• NO: 
  Topics to be discussed include:
• Employee health benefits
• Whether we should negotiate for higher salaries
• Frank Wetherby's retirement
• Cancelling our child care contract
  (This list is a mixture of noun phrases, dependent clauses, and gerunds)
• YES: 
  Topics to be discussed include:
• Employee health benefits
• Negotiations for higher salaries
• Frank Wetherby's retirement
• Cancellation of our child care contract