Grammar guide Updated 2026-09-14
Conjunctions: How to Teach and, but, or, so to ESL Beginners
Four words do most of the joining in everyday English: and, but, or and so. Most beginner mistakes here come from one decision, not from the words themselves: which relationship the second half has with the first. Below are the four meanings, the punctuation and a five-step lesson.
Four words, four jobs
Teach the words by meaning, not by label: learners who know that but signals a surprise stop confusing it with and.
| Word | What it signals | Example |
|---|---|---|
| and | more of the same | I like tea and I like coffee. |
| but | a contrast or surprise | I like tea, but I do not like coffee. |
| or | a choice between two things | Would you like tea or coffee? |
| so | a result | It was late, so we went home. |
A test that works in class: cover the second half. If it adds information, use and; if it takes something back, use but.
and: the default joiner
And joins two words, two phrases or two full sentences, and in a list of three or more items it goes before the last one: bread, cheese and tomatoes.
When and joins two subjects the verb follows the usual rule, so my brother and I are late takes the plural form; the subject-verb agreement guide covers that pattern in full.
but: a contrast
But tells the listener to expect a turn: I like tea, but I do not like coffee sets up two facts in opposition, and the second carries the new information.
Keep but apart from however, which is not a conjunction: I was tired. However, I stayed needs a full stop in front, while I was tired, but I stayed does not.
or: a choice
Or offers alternatives: tea or coffee, today or tomorrow. In questions it turns a statement into an invitation to choose, and the answer often reuses one of the two words with no verb at all: Coffee, please.
Or also softens an offer, which is why it appears so often in suggestions: Shall I call you or send an email?
so: a result, not a reason
So introduces what happened because of the first half: It was late, so we went home. The word for a reason is because, and beginners mix the two up constantly, so keep the pair on the board together.
Do not confuse so with the so ... that pattern that means very: It was so late that we missed the bus is a different structure and belongs in a later lesson.
Where the comma goes
Punctuation is the part learners notice least and markers notice most, so teach one rule with two examples.
| Sentence | Verdict | Why |
|---|---|---|
| I was tired, but I stayed. | correct | Comma before but joining two full clauses. |
| I was tired but stayed. | correct | No subject in the second half, so no comma. |
| I like tea, I like coffee. | incorrect | Two sentences need a full stop or a joining word. |
| Bread, cheese, and tomatoes. | acceptable | Serial comma: follow the style your school uses. |
A five-step lesson
Sentences first, labels last. Each step is short and the class produces something.
| Step | Teacher shows | Learners do |
|---|---|---|
| 1 | I like tea. I like coffee. | Say both facts as one sentence with and. |
| 2 | I like tea. I dislike coffee. | Choose and or but and explain the choice. |
| 3 | A café menu with two options. | Order with or, then answer with one word. |
| 4 | It was late. We went home. | Join with so and then with because. |
| 5 | Six pairs of short sentences. | Combine each pair and say which meaning they chose. |
Practice that turns the choice into a habit
These words are easy to recognise and easy to forget under pressure, because the learner decides on a meaning before choosing a word. Sentence combining trains exactly that: give six pairs of short sentences, ask for one joined version of each, and check the meaning, not only the punctuation.
Print the pairs as a worksheet with an answer key so the class can compare their choices, or build a fresh set from your own vocabulary in the worksheet builder. The grammar drills give quick practice on the same forms, and the timed challenge helps once the meanings are secure. Longer sentences come next in the relative clauses guide.
Errors worth correcting first
- Comma splice. I was tired, I went home needs and, but or so.
- So instead of because. We stayed inside so it was raining reverses the cause and the result.
- But where the meaning adds. I am tired but I am hungry states two facts; and joins them honestly.
Browse the grammar drills Print a worksheet Build your own set
Frequently asked questions
What is the difference between and, but, or and so?
Each one signals a different relationship between the two halves: and adds information, but contrasts it, or offers a choice, and so gives a result. Tea and coffee adds; tea but not coffee contrasts; it was late, so we went home gives a result.
Do I need a comma before and, but, or, so?
Put a comma before but, or and so when they join two complete sentences: I was tired, but I stayed. In a list of three or more items, place a comma before and if your school or exam board asks for the serial comma.
What is the difference between so and because?
So introduces the result and because introduces the reason: it was raining, so we stayed inside means the rain caused the decision, while we stayed inside because it was raining gives the same facts in the other direction. Both keep normal statement order.
Can I start a sentence with and or but?
Yes, and writers do it constantly for emphasis. It is a style choice rather than a grammar error, so it is allowed in moderation, especially in formal writing where a comma and but usually reads better.
Why do my students write I like tea, I like coffee?
Because they are joining two sentences in their heads without choosing a word to do the job, a habit carried over from a first language that allows comma splicing. Show the same pair three times — with and, with but, and as two sentences — and ask which meaning they wanted.
Keep reading
Every guide on this blog is paired with a free drill: the same rules, applied question by question, with explanations and a printable worksheet.