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Seven tiny words do an outsized amount of grammatical heavy lifting in English: for, and, nor, but, or, yet, so. They are the coordinating conjunctions — the bits of glue that hold equal parts of a sentence together, whether those parts are single words, short phrases, or full independent clauses. Most English students learn them by the mnemonic FANBOYS, an acronym that lines up the first letter of each one. This guide walks through all seven conjunctions, the punctuation rules that go with them, and the places writers most often trip up.
Table of Contents
What a Coordinating Conjunction Actually Does
The word "coordinating" is doing the explaining here. These conjunctions coordinate — they yoke together parts of a sentence that carry the same grammatical weight. Two nouns, two phrases, or two full clauses. Compare that with a subordinating conjunction, which deliberately makes one clause hang off another.
Two words: "salt and pepper"
Two phrases: "on the porch or in the garden"
Two clauses: "The deadline moved, so the team kept working."
The FANBOYS Mnemonic at a Glance
| Letter | Conjunction | Function |
|---|---|---|
| F | for | Reason/cause |
| A | and | Addition |
| N | nor | Negative addition |
| B | but | Contrast/exception |
| O | or | Alternative/choice |
| Y | yet | Contrast/surprise |
| S | so | Result/consequence |
F — For
Used as a coordinating conjunction, "for" is a formal synonym of "because" or "since." It points back at the previous clause and supplies a reason for it. You hear it more in literary prose than in everyday speech, where "because" usually does the job.
"He slipped the note into his pocket, for the hallway was crowded."
"They kept the lights dim, for the patient was asleep."
"I'll be brief, for the train leaves in ten minutes."
A coordinating "for" always follows the first clause — it cannot kick off a sentence. And when it joins two independent clauses, a comma comes right before it.
A — And
"And" is the workhorse of the seven. It simply adds — signaling that both sides of the conjunction are in play at the same time.
"The puppy barked and wagged its tail."
"The weather cleared, and the hikers pushed on."
"The apartment is bright and quiet."
"The menu offered soup, salad, and pasta."
N — Nor
"Nor" carries a second negative on the heels of a first negative. It often shows up alongside "neither," or simply after a clause that already contains a negation. When "nor" joins two independent clauses, the second clause inverts its subject and auxiliary (like a question):
"He doesn't play chess, nor does he understand the rules."
"The manager never apologized, nor did she explain the delay."
"Neither the host nor the guests noticed the power go out."
"I can't drive stick, nor can my brother."
B — But
"But" flags a contrast, an exception, or something the reader was not expecting:
"The task looked easy but took all afternoon."
"I planned to stay home, but the phone rang."
"Critics panned the album, but fans made it a hit."
"She isn't a lawyer, but she's read every contract twice."
O — Or
"Or" offers a choice, a substitute, or a range of possibilities:
"Paper or plastic?"
"We can drive tonight, or we can fly in the morning."
"Finish the report, or the whole team falls behind."
"Is that a hawk or a large crow?"
Y — Yet
"Yet" behaves a lot like "but," but with an extra flavor of surprise — a "despite what you just heard" kind of twist:
"The river was freezing, yet the dog jumped right in."
"The test covered one chapter, yet half the class failed."
"She had never touched a camera, yet her first photos won a prize."
S — So
"So" points at the result or consequence that follows from the first clause:
"The printer jammed, so we emailed the files instead."
"She trained for months, so the marathon felt manageable."
"The market was closed, so we grilled leftovers."
"His phone died, so he borrowed mine."
How Commas Work with FANBOYS
Two Independent Clauses: Add a Comma
When a FANBOYS word fuses two clauses that could each survive on their own, set a comma in front of the conjunction:
✓ "The kettle whistled, and the cat fled the room."
✓ "I was freezing, but I refused to go inside."
Two Words or Two Phrases: Skip the Comma
If the conjunction is merely linking two words, two phrases, or two verbs that share a single subject, leave the comma out:
✓ "She writes and edits her own newsletter." (Shared subject — no comma.)
✗ "She writes, and edits her own newsletter." (Unneeded comma.)
The Serial (Oxford) Comma
In a list of three or more items, "and" or "or" comes before the final item. The comma tucked in before that final conjunction — the Oxford comma — is strongly recommended for clarity:
"We invited Maya, Jamal, and Priya." (Oxford comma — the clearer choice.)
"We invited Maya, Jamal and Priya." (No Oxford comma — acceptable in some styles.)
Linking Words and Phrases
Coordinating conjunctions do not need full clauses to work. They happily yoke matched words or phrases of any kind:
Nouns: "bread and butter"
Adjectives: "small but loud"
Verbs: "bike or walk"
Prepositional phrases: "at the office or from home"
Infinitive phrases: "to write and to revise"
One thing to watch: the elements you link should be parallel. Pair a noun with a noun, a participle with a participle, a phrase with a phrase of the same shape. Mismatched structures read as off-balance even when each half is technically correct.
Beginning a Sentence with a Conjunction
Can a sentence open with "And," "But," or "So"? Generations of students were told no. The real answer is yes — nothing in English grammar forbids it, and the move has been standard in literary prose for centuries. Leading with a coordinating conjunction can add emphasis, keep a conversational rhythm, or smooth a transition between paragraphs:
"But nobody was listening at that point."
"And just like that, the contract was signed."
"So what does any of this change?"
Keep the habit rare in strictly formal academic writing, but do not bend over backward to avoid it on the basis of a rule that was never really there.
Where Writers Go Wrong
1. Comma Without a Conjunction (the Comma Splice)
✗ "The rain stopped, we headed out."
✓ "The rain stopped, so we headed out."
2. A Comma Before a Conjunction That Joins Non-Clauses
✗ "He opened the book, and began reading." (No second subject — one clause.)
✓ "He opened the book and began reading."
3. Piling "But" and "However" Together
✗ "The talk was short, but however, it was powerful." (Redundant.)
✓ "The talk was short, but it was powerful."
✓ "The talk was short; however, it was powerful."
4. Broken Parallelism
✗ "He enjoys reading, gardening, and to cook."
✓ "He enjoys reading, gardening, and cooking."
Try It Yourself
Fill in the missing FANBOYS conjunction and the punctuation that belongs with it:
- "He loved the city ___ he moved there the first chance he got."
- "The recipe looked complicated ___ it came together in twenty minutes."
- "You can finish tonight ___ you can pick it up tomorrow morning."
- "She rarely complains ___ does she ask for favors."
- "The coach was pleased ___ the team had exceeded every target."
Answers: 1. ", so" (result). 2. ", yet" (surprise/contrast). 3. ", or" (alternative). 4. ", nor" (negative addition). 5. ", for" (reason).
The short version: FANBOYS names the only seven coordinating conjunctions English has — for, and, nor, but, or, yet, so — and each one joins elements of equal grammatical rank. Put a comma before one when it connects two independent clauses; leave the comma out when it connects words, phrases, or a compound verb with a shared subject. Handle those punctuation rules well and most sentence-level grammar falls into place.