Conjunctions And, But, Or, So and Because: Rules and Examples
And, but, or, so and because are the five small words that turn short, separate sentences into real, connected English. Here is what each one means, where the comma goes and the mistakes learners make most.
By LearnLingo Team · Updated
Form
| Conjunction | Job | Example |
|---|---|---|
| and | adds information or a second action | I had a shower and went to bed. |
| but | shows a contrast or a surprise | The hotel was old, but it was very clean. |
| or | gives a choice or an alternative | Do you want tea or coffee? |
| so | shows a result | I was hungry, so I made a sandwich. |
| because | gives a reason | I made a sandwich because I was hungry. |
And, but, or and so join two equal parts of a sentence. Because starts a reason clause, and that clause can come at the end or at the start of the sentence.
| Pattern | Comma? | Example |
|---|---|---|
| two short clauses with and | usually no comma | I cooked and she washed up. |
| two clauses with but | usually a comma before but | It's small, but it's comfortable. |
| two clauses with so | usually a comma before so | The shop was closed, so we went home. |
| because clause at the end | no comma | We went home because the shop was closed. |
| because clause at the start | comma after the reason | Because the shop was closed, we went home. |
| a list of three or more | commas between items | I bought eggs, milk and bread. |
Before the last and in a list, American English often adds a comma (eggs, milk, and bread). British English often leaves it out. Both are correct; just be consistent.
| Order of ideas | Word | Example |
|---|---|---|
| reason first, then result | so | The bus was late, so I missed the start of the film. |
| result first, then reason | because | I missed the start of the film because the bus was late. |
| reason first, as a full clause | Because ..., ... | Because the bus was late, I missed the start of the film. |
And: adding information
We use and to join two ideas that go together: two things, two actions, two adjectives or two full sentences. It simply means plus or also.
When the subject is the same in both parts, we usually do not repeat it: I got up and made breakfast, not I got up and I made breakfast (that is correct, but it sounds slow). In a list of three or more things, we put commas between the items and use and only before the last one: red, white and blue.
And can also show that one action happens after another. I opened the door and saw a cat means first I opened it, then I saw the cat.
My brother and I share a room.
She speaks Turkish, English and a little German.
I finished work and went straight to the gym.
The beach was quiet and the water was warm.
Come and see my new flat.
Come and, go and, try and are very common in speech before another verb.
But: contrast and surprise
We use but when the second idea is different from the first, or when it is a little surprising after the first idea. It often joins a positive and a negative idea.
In writing, put a comma before but when it joins two full sentences: The film was long, but I enjoyed it. With two short words, no comma is needed: small but comfortable.
Starting a sentence with But is common in messages, stories and journalism. In formal or academic writing, however is often a safer choice. For more ways to show contrast, see linking words of contrast.
I like coffee, but I don't drink it at night.
The flat is small but comfortable.
We wanted to go out, but it started to rain.
He's only nine, but he can cook a full dinner.
Sorry, but I can't come on Saturday.
Sorry, but is a polite way to say no.
Or: choices and alternatives
We use or to give a choice between two or more things. It is very common in questions: Tea or coffee? Do you want to walk or take the bus?
In negative sentences, use or, not and, to join two things you do not have or do not do: I don't eat meat or fish. This means I eat neither of them.
Or else and or can also mean if not, when you warn someone: Hurry up, or we'll miss the train. For the pattern either ... or, see both, either and neither.
Would you like rice or potatoes with your chicken?
We can meet on Friday or Saturday.
I don't have a car or a bike.
In negatives, or joins the two things.
Put your coat on, or you'll get cold.
So and because: result and reason
These two words connect a cause and its effect, but from opposite directions.
Because introduces the reason. It answers the question Why?: Why are you tired? Because I didn't sleep well.
So introduces the result. It tells you what happened next: I didn't sleep well, so I'm tired.
The facts in these two sentences are the same. Only the order changes. A good test: if you can ask Why? before the second part, use because. If you can ask What happened then?, use so.
Never use because and so for the same idea in one sentence. Because I was tired, so I went home is a very common mistake. Choose one: Because I was tired, I went home, or I was tired, so I went home.
Also remember that because of is followed by a noun, not a full clause: We stayed inside because of the rain, but We stayed inside because it was raining.
I'm learning English because I want to work abroad.
I want to work abroad, so I'm learning English.
Because the tickets were expensive, we stayed at home.
The road was closed because of the snow.
Because of + noun.
It was my mum's birthday, so I baked a cake.
Why are you laughing? Because this video is so funny!
In spoken answers, a short Because ... answer on its own is normal.
Word order and starting sentences
And, but, or and so must come between the two ideas they join. You cannot move them to the start of the first idea: So I was hungry, I ate is wrong.
Because is more flexible. The because clause can come at the end (no comma) or at the start (with a comma after it). Put it at the start when you want to stress the reason.
In speech, people often begin with And, But or So to continue a story: So, what did you do next? And then the lights went out! This is natural in conversation and informal writing. In exams and formal writing, it is safer to join the ideas inside one sentence. The blog post on linking words shows more formal options like therefore and however.
So, how was your weekend?
So at the start is a common way to begin a new topic in conversation.
And then my phone died.
Because it was late, the restaurant was almost empty.
In real life
In everyday speech, people use these five words all the time to tell stories, give excuses and make plans. Listen for them in films and podcasts and you will notice that so and but are often used to keep a conversation moving.
Try to use at least two conjunctions every time you describe your day. Instead of I got up. I had breakfast. I went to work, say I got up, had breakfast and went to work, but the bus was late, so I took a taxi. You sound more fluent at once. For more practice building longer sentences, read how to improve your English writing.
I'd love to come, but I'm working late tonight.
My phone was dead, so I couldn't call you.
Do you want to stay in or go out tonight?
I'm a bit quiet today because I'm really tired.
Common mistakes
Because I was tired, so I went to bed.
Because I was tired, I went to bed. (or: I was tired, so I went to bed.)
Because and so describe the same cause and effect from two directions. Use only one of them in a sentence.
I stayed home because the rain.
I stayed home because of the rain.
Because is followed by a full clause with a subject and verb (because it was raining). Before a noun alone, use because of.
I don't like football and tennis.
I don't like football or tennis.
In negative sentences, or joins the two things you don't like. With and, the sentence can sound like you only dislike them together.
I was late. Because I missed the bus.
I was late because I missed the bus.
In writing, a because clause is not a complete sentence on its own. Join it to the main clause. A short Because ... answer is fine only in speech, after a Why question.
So I was hungry, I made a sandwich.
I was hungry, so I made a sandwich.
So must come between the reason and the result, at the start of the result. It cannot introduce the reason at the start of a sentence.
Practice quiz
10 questions. Pick an answer to see if it is right and why.
1. I was thirsty, ___ I drank a glass of water.
2. I drank a glass of water ___ I was thirsty.
3. The test was difficult, ___ I passed it.
4. Choose the correct sentence.
5. Do you want pasta ___ pizza?
6. She doesn't eat meat ___ eggs.
7. We cancelled the picnic ___ the rain.
8. What does It was late, so we took a taxi mean?
9. Choose the sentence with correct commas.
10. I got up early ___ went for a run.
0 of 10 answered
Show all answers
- so
- because
- but
- Because it was cold, we stayed in.
- or
- or
- because of
- It was late, and that is why we took a taxi.
- I bought apples, bananas and grapes.
- and
See what the A2 English course covers, or test your level first.
People also ask
What is the difference between so and because?+
Because gives the reason and so gives the result. I'm tired because I worked late and I worked late, so I'm tired describe the same situation in a different order. Never use both for the same idea in one sentence.
Can I start a sentence with because?+
Yes. Because it was raining, we stayed inside is correct, with a comma after the reason. What you should avoid in writing is a because clause on its own, like Because it was raining. with nothing else.
Can I start a sentence with and or but?+
In speech and informal writing, yes, and it is very common. In formal writing and exams, it is usually better to join the ideas in one sentence or use words like also and however.
Do I need a comma before and?+
Usually not when you join two short ideas. In a list, American English often puts a comma before the last and (red, white, and blue), and British English often does not. Both styles are accepted.
What are these words called?+
And, but, or and so are coordinating conjunctions: they join two equal parts. Because is a subordinating conjunction: it starts a clause that depends on the main clause. You do not need the names to use them well.
Related reading
Linking Words and Connectors
A guide to English linking words and connectors for adding, contrasting, giving reasons, results, examples and sequence, with examples.
6 min readCommon Mistakes · A2English Word Order: Subject, Verb, Object
How English word order works: subject, verb, object, plus where to put adverbs, adjectives, time and place, with examples and a quiz.
7 min readCommon Mistakes · A2English Punctuation Basics
The basic rules of English punctuation: periods, commas, question marks, apostrophes, colons, semicolons and quotation marks, with examples.
6 min readLearning Tips · B1
How to Improve Your English Writing
Practical ways to improve your English writing: write short texts often, use linking words, edit with a checklist, learn from model texts and fix common errors.
6 min read