Conjunctions are words or phrases used to join two clauses. They can be coordinating conjunctions, or subordinating conjunctions, relative pronouns, or relative adverbs.

Coordinating conjunctions

AND               BUT                OR                  SO                  YET               FOR

Coordinating conjunctions serve two purposes:

1) to join independent clauses in a particular relationship, and 2) to create compound subjects and predicates (complements to verbs), again, in a particular relationship. In other words, each conjunction has a specific function to perform in joining elements of a sentence.
Thus there are several elements of the coordinating conjunction that need to be mastered:

  1. Understanding each conjunction’s specific function;
  2. Knowing when to reduce the second clause to a phrase;
  3. How to treat compound subjects;
  4. When, and when not to use commas;
  5. Beginning a sentence with a conjunction;
  6. Conjunction expressions (both…and…, either…or…, etc.).

1. Functions

And– used to bridge ideas that follow from each other, to add to an idea; to unite individual subjects and predicates into unified wholes; to group items in a list, or end a list.

  • The invitations had been sent out weeks ago, and RSVPs have already started to arrive.
  • The invitations have been received and the RSVPs confirmed.
  • The guests and their dates have begun to arrive
  • The band played the latest hits and some traditional songs for the older guests.
  • The newlyweds received many expensive gifts, like crystals, jewellery, and artworks.

But– used to indicate a contrasting idea, a positive to negative relationship, or unexpected information.

  • Jane has earned a spot on the Olympic swim team, but her injury might prevent her from joining the competitions.
  • Her coach encourages her daily but he also wants her to prepare for the worst.
  • She had been injured before, but never this badly.
  • Jane really wants to go, but she’ll be happy to cheer her teammates on TV as well.

Or– used to indicate alternative information to what has been given; to provide options, choices.

  • The only plausible solution at this stage is to sell off stocks and hope for a good return, or we can consider the possibility of bringing in a partner with capital.
  • We can also reduce staff numbers or, at minimum, freeze salaries and bonuses.

Nor–used similarly to and to indicate adding a negative idea to a negative idea. It is not used as a negative to or. The clause that follows nor is often used with an inverted structure (see examples). It is important to note that nor is a highly formal construction and is not commonly used these days.

  • No witnesses came forward to help the police in their investigation, nor were any expected to, given the political implications of the affair. (Can be rewritten as: No witnesses came forward…, and none were expected to ….)
  • In fact, the newspapers reported that no criminal activity occurred, nor any reason to believe it had.

Yet– similar to but, this conjunction is used to show contrast to an expected outcome. It is used instead of but to suggest that two contrasting ideas occur simultaneously.

  • Belinda accepted her son’s story, yet she could not quite believe it.
  • The school staff confirmed that no violence had been witnessed at the school, yet they could not explain the injuries to Steven’s face.
  • It is sunny outside, yet cold.

So– used to show a result, or consequence.

  • All flights have been cancelled due to the bad weather, so we will have to find lodgings for tonight.
  • The cheating student would not confess, even when presented with video evidence of his action, so the university has no option other than to expel him.

For– used to indicate a reason (similar to because), though using for as a conjunction is not recommended. It is more formal and old-fashioned than will generally be required of you in academic writing.

  • Humans can communicate even imaginative ideas with each other, for they have been blessed with the gift of language.

2. Reducing Coordinate Clauses

An important aspect of coordination using conjunctions is parallelism. This means that we must have parallel (or same, equal) structures on both sides of the conjunction. For example, we cannot write I like swimming and to play basketball. We must choose one structure and use it on both sides of the conjunction, as in:

I like to swim and (to) play basketball. Or,

I like swimming and playing basketball. (NB. Like is a verb that can be followed by either an      –ing verb or an infinitive verb. Other verbs must be followed by one or the other, which would make the choice in terms of the parallel structure easier)

With parallelism in mind, we can look at two clauses joined by a conjunction and begin to eliminate repetition. More specifically, we can cut out subjects, when they are the same in both clauses, or verbs, even prepositions and other parts of modifiers in the clause that are unnecessary because they are ‘carried over’ from the first clause.

Let’s look at some examples:

I enjoy reading and I enjoy writing. – in this simple case, both subject and verb repeat in the second clause, so can be eliminated: I enjoy reading and writing.

The company’s main priorities are to increase sales and to attract new customers. – in this sentence, the parallel structure appears in the subject complement following the verb are. The only repetition is of the infinitive to. The sentence can therefore be reduced to The company’s main priorities are to increase sales and attract new customers. Remember that eliminating repetition is an option, not a rule. If you favor the extra to, keep it. Do not forget, however, that once that decision is made, it must ‘carry over’ throughout the sentence. For instance, The company’s main priorities are to increase sales, attract new customers, and to appease shareholders. In this last sentence, you must either add the infinitive to before the verb attract, or remove it from before the verb appease.

The courier delivered the customs documents, but he did not deliver the actual goods.

The courier delivered the customs documents, but not the actual goods.  –in these two statements, the only differences are a) the subject is identified in the first and represented by a pronoun in the second; this does not matter—you are not eliminating a repetitive word, but rather a repetitive subject; b) delivered is opened up into its full form, did deliver, to allow for the adverb, not. Again, you are eliminating repetitive verbs, not words.

You can try again tomorrow, or you can take some time to review and come back next week.

You can try again tomorrow, or take some time to review and come back next week.

If you are not sure if the verb ‘carries over’ include it in the second clause, especially if the subject has changed.

I had the burger, and Kathy the fries.

I had the burger, and Kathy had the fries.

The most important thing to remember when reducing a coordinated clause is to make sure the meaning of the reduced clause (now a phrase because it contains no subject and verb) is maintained.

3. Compound Subjects

Sentences that have a compound subject, that is, those with two nouns joined by a conjunction in whichever relationship, need to agree with their verb accordingly. While compound subjects joined by and will always be plural, those joined by the other conjunctions are not as simple.

Justine and Felicia are friends.

Aaron and his brothers play hockey.

The company and its shareholders have a vested interest in the outcome of the election.

NB: When we join subject elements with expressions such as well, along with, etc., agree the verb with the first subject element ( Alex, along with his two sisters, goes to church every Sunday).

When we look at or and nor, we have to pay special attention to the components of the subject. (but, yet, and so do not join subject elements).

In sentences with subjects joined by or or nor, there are two approaches: 1 – if both subject elements are plural, then the verb agrees with the plural subject. If at least one of the subject elements is plural, then the verb agrees with a plural subject. 2 – the verb agrees with the subject closest to it. In this case, if the second subject element is plural, so too will the verb agreement be.

Neither Ben nor Scott has a car.

Neither the buses nor the plane were on time today.

Either the flowers or the plant have to go.

Neither Clare nor her sisters are married.

Recommended: approach 2—match the verb to the subject element nearest the verb.

4. Comma Usage

In a list, always use the comma before the and to indicate the last item in a list (This is called the serial comma and is recommended by Chicago Manual of Style). Do not use a comma when joining only two elements as object or complement.

When joining clauses, you do not always need a comma. It is acceptable, especially with short and direct clauses to omit the comma. Think of the comma, then, as a signal for pause. If the sentence as a whole does not require that pause (in order to shift attention to a new idea), then it does not require the comma. Also, if the conjunction would closely follow another comma, then you might be better off not including it.

I love people and I love dogs, but if I had to choose, I’d choose the dogs. (The repeated I love is for emphasis.)

After spending too many hours together at the hotel, I went to the beach and Vanessa went to the mall.

5. Sentence Beginning

Many teachers have drilled into their young students’ minds that “one should never begin a sentence with a conjunction.” Most likely, they feel that avoiding such sentences is the surest way to prevent fragmented or run-on sentences from being written. Keep in mind that there no rule that states that a sentence that begins with a conjunction is wrong. Please also keep in mind why teacher’s worry about it.

If you are presenting an argument, and you have written a long sentence that clearly expresses a complete idea and you want to end it, but you also want to add more to that idea, it is perfectly alright to begin the next sentence with and. If you want to emphasize a contrasting position to one just mentioned, by all means begin the next sentence with but. Yet is also commonly used to begin a sentence, as is or. So and for are less commonly used  this way.

Pay careful attention to what is being joined in these cases. Usually, the conjunction will be used to join one idea to another, that is, one sentence’s whole idea (even if more than one is presented in the sentence by use of other conjunctions) is joined to another sentence’s whole idea.

Example: Justin and Caleb studied together for their Biology exam, and while Caleb read out loud the required material, Justin took notes, highlighting what he felt to be key points and then sharing these with Caleb when they were done. But on test day, Caleb panicked, and Justin could see the sweat roll down the side of his friend’s face and knew that something was wrong.

But on test day suggests that even with all the preparations prior to the test, and the seeming readiness, something bad happened during the actual test.

6. Expressions

Some conjunctions are used with fixed expressions, such as:

Both… and…: used to unite two things, people, places, etc., into one unit.

Either… or …: used to individualize two things, people, etc.

Neither … nor…: same as either, but in a negative context.

Not only… but also…: similar to both/and, though allows for other structures besides nouns (can be followed by a clause)

The key here is to remember that the expressions are usually found intact in writing, meaning that you will not see half the expression and not the other. This is a common mistake for test takers.

The company would love to hire both you and your brother. Unfortunately, we cannot afford both of you, but since we are equally impressed by each of you individually, we are prepared to make an offer to either you or him.

I’m sorry, sir. Neither my brother nor I are prepared to accept your offer. Not only would it be difficult for us to be apart, it would also kill our mother to hear that one of us is working while the other continues to search.

Other conjunctions:

When joining an independent clause to a dependent clause, you will still need to use a conjunction. These conjunctions, however, have other purposes than the coordinating conjunctions and follow the rules of the clause type. To learn these in greater detail, study the pages for each clause type.

Noun clause conjunctions: (relative pronouns and subordinating conjunctions)

what            whatever             how                  however

who             whoever              whom               whomever

which          whichever           where                when

why              whose                 that                    whether/if

Adjective clause conjunctions: (relative pronouns and relative adverbs)

that             who                   where             whose

which          whom                when              (why)

Adverb clause conjunctions: (subordinating conjunctions; these are some of the most common)

after            till               although            if           unless          as in

as much       until            as if             when           as long as     whenever

as much as   where          as soon as    provided      wherever      as though

since            while           because        so that         before          than

even if         even though   though

Clauses and Phrases