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Read this: "I woke up late. I missed the bus. I was worried. I would be late for the interview. I ran to the office. I made it on time. I was relieved." Every sentence there is grammatically correct. None of them are connected to each other, so the whole thing reads like a list of facts rather than something a person would actually say. Now read it again: "I woke up late and missed the bus, so I was worried I'd be late for the interview. Although I ran to the office, I made it on time, and I was relieved." Same seven facts, same information โ but only the second version sounds fluent. That's the entire job of a conjunction: not adding new content, but showing the reader exactly how the pieces of information relate to each other โ which one caused which, which ones contrast, which ones simply add up.
English conjunctions fall into three families. Most courses only teach the first two and skip the third entirely, which is a shame, because the third family is where a surprising number of mistakes happen in otherwise advanced writing.
1. Coordinating conjunctions: FANBOYS
Seven words, easy to memorize with the acronym FANBOYS: for, and, nor, but, or, yet, so. Each one joins two words, phrases, or complete sentences that carry equal grammatical weight โ neither side depends on the other to make sense on its own.
| Conjunction | Function | Example |
|---|---|---|
| for | reason (formal, rare in speech) | She left early, for she had an early flight. |
| and | addition | He studies English and French. |
| nor | adding a second negative option | She doesn't like coffee, nor does she like tea. |
| but | contrast | The test was hard, but she passed. |
| or | alternative | You can call or email me. |
| yet | contrast, often surprising | He's rich, yet he lives simply. |
| so | result | It was raining, so we stayed inside. |
The comma rule: when a coordinating conjunction joins two complete sentences โ each with its own subject and verb โ put a comma before it: I called her, but she didn't answer. When it's only joining two words or phrases, not two full sentences, skip the comma: I called her but got no answer. The quick test: cover up everything after the conjunction and check whether what's left before it could stand alone as a sentence.
2. Subordinating conjunctions: organized by relationship, not the alphabet
Subordinating conjunctions attach a dependent clause โ one that can't stand alone โ to an independent one. There are dozens of them, but instead of memorizing a flat list, it's far more useful to group them by what relationship they express:
- Cause or reason: because, since, as โ I stayed home because I was sick.
- Contrast: although, even though, though, whereas, while โ Although it was raining, we went for a walk.
- Condition: if, unless, provided that โ I'll come unless something changes.
- Time: when, while, before, after, until, as soon as โ Call me when you arrive.
- Purpose: so that, in order that โ She whispered so that no one would hear.
The comma rule: when the dependent clause comes first, add a comma after it: Because I was sick, I stayed home. When the independent clause comes first, skip the comma: I stayed home because I was sick. Same sentence, same meaning either way โ the comma is purely a function of word order, not meaning.
3. Correlative conjunctions: they come in pairs, and both halves have to match
This is the family most courses skip. Correlative conjunctions always work in matched pairs, and the grammatical structure following the first half has to mirror the structure following the second half exactly:
- both ... and โ She speaks both French and Spanish.
- either ... or โ You can either call or text me.
- neither ... nor โ He neither called nor texted.
- not only ... but also โ She is not only smart but also hardworking.
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The parallel structure rule: whatever grammatical form follows the first word of the pair must match what follows the second. She is not only smart but also she works hard pairs an adjective (smart) against a full clause (she works hard) โ mismatched weight on each side of the scale. She is not only smart but also hardworking pairs two adjectives, and suddenly the sentence balances the way the conjunction pair is built to balance.
Common mistakes
- Doubling up "although" and "but" in one sentence.
Although it was raining, but we went outโ Although it was raining, we went out. - Using "despite" like a conjunction.
Despite it was raining, we went outโ Despite the rain, we went out (or Although it was raining...). - The comma splice โ joining two independent clauses with only a comma, no conjunction.
I was tired, I went to bed earlyโ I was tired, so I went to bed early. - Breaking parallel structure in a correlative pair.
Either you apologize or leavingโ Either you apologize or you leave. - An unattached subordinate clause, left as a fragment.
Because I was late.(standing alone) โ Because I was late, I missed the bus.
Back to where we started
The seven choppy sentences at the top of this article and the two fluent ones right after them contain exactly the same information. Conjunctions are the only thing separating them โ and they're doing real grammatical work in both directions, joining equal ideas, attaching dependent ones, and pairing matched structures. None of that shows up as new vocabulary on a test; it shows up as the difference between writing that's technically correct and writing that actually sounds like a fluent speaker wrote it.
Frequently asked questions
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