What Is a Coordinating Conjunction?
A conjunction is a word that connects elements in a sentence. Coordinating conjunctions specifically connect elements of equal grammatical rank: word to word, phrase to phrase, or independent clause to independent clause. They do not introduce dependent clauses; that is the job of subordinating conjunctions.
The seven coordinating conjunctions are: For, And, Nor, But, Or, Yet, So — FANBOYS.
Each Conjunction Explained
For
For as a coordinating conjunction means "because" or "since." It gives a reason. It is more formal than the other conjunctions and appears mainly in written prose.
- She did not attend, for she was feeling unwell.
- He studied every evening, for the exam was only days away.
Note: for as a coordinating conjunction is different from for as a preposition (a gift for you). As a conjunction, it joins two independent clauses.
And
And adds one element to another. It signals addition, continuation, or a sequence of events.
- She drafted the proposal and submitted it before noon. (joining two verbs)
- The report was thorough and well-organized. (joining two adjectives)
- The deadline passed, and the contract was awarded to a competitor. (joining two independent clauses)
Nor
Nor joins two negative alternatives. It follows a negative statement and introduces a second negative element. It is almost always preceded by neither or a negative clause.
- She did not call, nor did she send a message.
- The report was neither complete nor accurate.
- He had no time, nor did he have any interest in the project.
When nor joins two independent clauses, the subject and auxiliary verb in the second clause are inverted: nor did she, not nor she did.
But
But signals contrast or exception. It introduces something that contradicts or limits what came before.
- The project was ambitious but achievable.
- She worked hard, but the results were disappointing.
- Everyone agreed except one member, but her objection was noted.
Or
Or presents alternatives or choices. It can also indicate a consequence or clarification.
- You can submit the form online or by mail.
- The team must meet the deadline, or the contract will be terminated.
- She will revise the draft, or a new one will be commissioned.
Yet
Yet as a coordinating conjunction signals contrast, similar to but, with a nuance of surprise or unexpectedness.
- The plan was simple, yet effective.
- He had little experience, yet he performed exceptionally well.
- The budget was tight, yet the team delivered on time.
Yet tends to feel more emphatic than but because it highlights the contrast more strongly.
So
So indicates a result, consequence, or purpose. The second clause follows as a result of the first.
- The data was incomplete, so the team delayed the report.
- She had an early flight, so she left the office at three.
- The feedback was positive, so the project moved forward.
Comma Rules with Coordinating Conjunctions
The comma rule is one of the most important things to understand about coordinating conjunctions:
- When a coordinating conjunction joins two independent clauses, place a comma before it.
- When a coordinating conjunction joins two words, phrases, or dependent clauses (not two full sentences), no comma is needed.
| Example | Comma? | Why |
|---|---|---|
| She revised the draft, and he proofread it. | Yes | Two independent clauses |
| She revised and proofread the draft. | No | Two verbs sharing one subject |
| The meeting was long, but it was productive. | Yes | Two independent clauses |
| The long but productive meeting ended at noon. | No | Two adjectives modifying a noun |
| Submit the form online or by mail. | No | Two phrases, one subject |
The quick test: can both sides of the conjunction stand alone as complete sentences? If yes, use a comma. If not, you probably do not need one. For the full rules on comma usage, see the guide on how to use commas.
Starting a Sentence with a Coordinating Conjunction
Many writers learn early that sentences should not begin with and, but, or so. This is not a grammatical rule — it is a stylistic preference from older writing instruction. Starting a sentence with a coordinating conjunction is acceptable in contemporary English, including in formal writing.
Done well, it creates emphasis and a short, punchy rhythm: The proposal failed. But the underlying idea was sound. Done too often, it makes writing feel fragmented. Use it sparingly and intentionally.
Coordinating vs. Subordinating Conjunctions
Coordinating conjunctions join elements of equal rank. Subordinating conjunctions introduce dependent clauses and show a hierarchical relationship between ideas:
- Coordinating: She worked hard, but she did not get the promotion. (two equal clauses)
- Subordinating: Although she worked hard, she did not get the promotion. (dependent + independent)
The key difference: a sentence with a subordinating conjunction has one main idea and one supporting idea. A sentence with a coordinating conjunction has two ideas of equal weight. The choice affects emphasis.
Common Mistakes
- Using a comma before a conjunction that joins words or phrases (not clauses): She was tired
,and hungry. - Using a conjunctive adverb (however, therefore) as if it were a coordinating conjunction. These require a semicolon, not a comma. See comma splices.
- Omitting the comma before a conjunction that joins two full independent clauses.
- Confusing nor with or in a negative context: after a negative, use nor, not or: He did not call nor did he write, not He did not call or did he write.
Frequently Asked Questions
How many coordinating conjunctions are there?
Exactly seven: for, and, nor, but, or, yet, so (FANBOYS). Some grammarians add yet to a separate category (it can also function as an adverb), but in its conjunctive function joining independent clauses, it is a coordinating conjunction.
Can I use a semicolon instead of a comma before a coordinating conjunction?
Only in one specific case: when the independent clauses already contain internal commas and the semicolon is needed for clarity. The project covered planning, research, and analysis; and the report summarized all three phases. This is the "serial semicolon" applied at the clause level. Outside this case, a comma before a coordinating conjunction is standard.
What is the Oxford comma and how does it relate to FANBOYS?
The Oxford comma is a comma placed before the final conjunction in a list of three or more items: apples, oranges, and pears. It involves and (or or) but is a separate convention from the comma-before-conjunction rule for independent clauses. Style guides differ on whether to use the Oxford comma; the rule for commas before conjunctions joining independent clauses is not disputed.
Is "for" a coordinating conjunction or a preposition?
Both, depending on its use. For is a preposition when it precedes a noun phrase: a gift for you. It is a coordinating conjunction when it joins two independent clauses meaning "because": She stayed home, for she was ill. The conjunction use is much less common in modern English than the preposition use.