What Is a Conjunction? Types, Rules, and Examples

A conjunction is a word used to link parts of a sentence: single words, phrases, or whole clauses. Instead of writing, "The train was late. We waited anyway," English lets us join the ideas: "The train was late, but we waited anyway." That small connecting word tells readers how the two thoughts fit together. Conjunctions can add information, show contrast, give a reason, offer a choice, or set a condition. Below, you'll find the main types of conjunctions, how they work, where punctuation belongs, and the errors that most often cause trouble.

What a Conjunction Means

The term "conjunction" traces back to the Latin conjunctio, or "a joining together." That origin matches the job exactly: conjunctions connect units of language. They belong to the eight traditional parts of speech. Like prepositions, they are usually treated as a "closed class," meaning English does not often add brand-new conjunctions.

Each conjunction signals a relationship. And adds. But contrasts. Because gives a cause. If introduces a condition. Or presents an alternative. Time words such as when, before, and after place one action in relation to another. Choosing the right connector helps readers follow your meaning and makes your sentence structure cleaner.

The FANBOYS Coordinating Conjunctions

Coordinating conjunctions join elements of equal grammatical value: word with word, phrase with phrase, or clause with clause. English has seven common coordinating conjunctions, often remembered as FANBOYS:

Of these, "and" appears most often. It ranks among the ten most frequently used English words. "But" and "or" are also extremely common. Together, these short words do a great deal of work in everyday speech and writing.

Joining Single Words and Short Phrases

"Maya bought apples and oranges." — Joins two nouns.
"The hallway was narrow but bright." — Joins two adjectives.
"The assistant replied politely and clearly." — Joins two adverbs.

Linking Complete Independent Clauses

When a coordinating conjunction connects two independent clauses, put a comma before the conjunction:

"The lights flickered, and the audience grew quiet."
"Carlos practiced for weeks, yet he still felt nervous."

Words That Subordinate Clauses

Subordinating conjunctions attach a dependent, or subordinate, clause to an independent clause. The result is a complex sentence. These conjunctions can show time, reason, condition, contrast, purpose, and other relationships:

Words That Show Time

when, while, before, after, since, until, as soon as, once, whenever

"Before the doors opened, a line formed outside."
"Nina has lived there since she started college."

Words That Give a Cause or Reason

because, since, as, now that, given that

"Because the printer jammed, the handouts were late."
"Since no one objected, we approved the plan."

Words That Set Conditions

if, unless, provided that, as long as, in case, even if, whether

"If the package arrives today, I'll bring it over."
"The meeting will continue unless the power goes out."

Words That Mark Contrast or Concession

although, though, even though, whereas, while

"Although the instructions were brief, the task was easy."
"Liam likes quiet mornings, whereas his sister likes late nights."

Words That Express Purpose

so that, in order that, lest

"They labeled every box so that the movers could unload quickly."

Paired Conjunctions

Correlative conjunctions come in pairs. They connect matching, balanced parts of a sentence:

• as...as — "The new clerk is as careful as the manager."
• whether...or — "She could not decide whether to call or wait."
• not only...but also — "The course is not only useful but also affordable."
• neither...nor — "Neither the lock nor the alarm was working."
• either...or — "We can either leave now or miss the bus."
• both...and — "Both the director and the editor approved the draft."

The main rule is parallel structure. The grammatical form after the first part of the pair should match the form after the second part. "He not only paints but also sculpts" works because both joined elements are verbs. "He not only paints but also a sculptor" does not work because it pairs a verb with a noun phrase.

Adverbs That Connect Ideas

Some adverbs behave like connectors by showing how one independent clause relates to another. Common conjunctive adverbs include however, therefore, moreover, furthermore, nevertheless, consequently, meanwhile, otherwise, instead, similarly, accordingly.

The usual punctuation is a semicolon before the conjunctive adverb and a comma after it:

"The results were incomplete; therefore, the researchers collected more samples."
"The first shipment arrived damaged; however, replacements came the next day."

Punctuation with Conjunctions

1. Subordinating conjunctions in the middle: A comma is usually unnecessary. "We stayed inside because the wind was strong."
2. Coordinating conjunctions joining words or phrases: Do not add a comma just for the conjunction. "Tea or coffee." "Quiet but firm."
3. Oxford comma: In a list of three or more items, the comma before the final "and" is recommended for clarity: "Pack socks, gloves, and a scarf."
4. Coordinating conjunctions joining independent clauses: Use a comma before the conjunction. "The dog barked, and the baby woke up."
5. Subordinating conjunctions at the beginning: Place a comma after the dependent clause. "Because the room was full, we stood in the back."

Starting Sentences with And, But, or Because

Yes, you can begin a sentence with a conjunction. The old warning against opening with "and," "but," or "because" is not a real rule of English grammar. Major style authorities, including the Chicago Manual of Style and Strunk and White, accept the practice, and skilled writers have used it for centuries.

"The hikers had no map. But they kept moving." The opening conjunction adds force and creates a pause that a single compound sentence would not give.

"And then the phone rang." Beginning with "and" can make a line feel connected to what came before, especially in narrative writing.

Use the technique on purpose. If every other sentence starts this way, the writing can begin to sound clipped or overly casual.

How Conjunctions Build Compound Sentences

Coordinating conjunctions are a standard way to form compound sentences. A compound sentence contains two or more independent clauses:

"The café was closing soon, so we ordered quickly."
"You can email the form, or you can drop it off in person."

Compound sentences give equal weight to related ideas. They also help create variety in sentence structure, which keeps prose from sounding flat.

How Conjunctions Build Complex Sentences

Subordinating conjunctions create complex sentences by turning one clause into a dependent clause:

"When the bell rang, the students closed their books." — The "when" clause is dependent; it cannot stand alone as a complete sentence.
"The fundraiser succeeded because volunteers promoted it early."

Complex sentences let writers rank ideas. One clause carries the main point, while the other supplies background, timing, cause, contrast, or condition.

Keeping Joined Elements Parallel

When a conjunction links two or more items, those items should normally follow the same grammatical pattern:

Correct: "Omar enjoys running, cooking, and gardening." (Three gerunds.)
Incorrect: "Omar enjoys running, to cook, and gardening." (Mixed forms.)

Correct: "The proposal was clear, practical, and persuasive." (Three adjectives.)
Incorrect: "The proposal was clear, practical, and won support." (Two adjectives + a verb phrase.)

Parallel structure improves rhythm and makes comparisons easier to follow. It is a simple way to make writing sound more controlled.

Errors Writers Often Make with Conjunctions

1. Broken parallelism: "They planned to swim and biking" should be "They planned to swim and bike" or "They planned swimming and biking."
2. Comma splice: This happens when two independent clauses are joined by only a comma. "The shop was closed, we went home" should be "The shop was closed, so we went home" or "The shop was closed; we went home."
3. Double conjunction: "Although the flight was delayed, but we arrived on time" uses both a subordinating and coordinating conjunction. Use one: "Although the flight was delayed, we arrived on time" or "The flight was delayed, but we arrived on time."
4. Run-on sentence: Independent clauses need a conjunction, punctuation, or both. "The shop was closed we went home" needs to be corrected.
5. Misusing "because": "The reason is because..." is wordy and redundant. Use "The reason is that..." or start directly with "Because..."

Try a Few Practice Items

Identify the conjunction type in each sentence:

1. "The museum was busy, yet the line moved quickly." — Coordinating (yet).
2. "Because the forecast changed, the picnic moved indoors." — Subordinating (because).
3. "Both the librarian and the volunteers sorted the donations." — Correlative (both...and).
4. "He missed the first bus; therefore, he took a taxi." — Conjunctive adverb (therefore).
5. "I'll call if the appointment changes." — Subordinating (if).

Conjunctions may be small, but they carry a sentence from one idea to the next. Learn how they connect equal parts, dependent clauses, paired structures, and related independent clauses, and your writing will become smoother and more precise. For more help with grammar, visit dictionary.wiki and see our basic English grammar guide.