Conjunctions are words that join words, phrases or clauses. There are three types: coordinating conjunctions such as and, but and so; subordinating conjunctions such as although, because and if; and correlative pairs such as both ... and and either ... or. Each type follows its own rules for word order and punctuation.
Coordinating conjunctions
Coordinating conjunctions join two parts of equal importance. The seven most common are for, and, nor, but, or, yet and so. Many teachers remember them as fanboys.
And adds an idea. But and yet show contrast. Or gives a choice. So shows a result. For gives a reason (it is formal and rare). Nor adds a second negative. They sit between the two parts they join: The city is expensive, but it offers many jobs.
When a coordinating conjunction joins two full clauses, put a comma before it. When it joins only two words or phrases, you do not need a comma: Students need time and support.
- I wanted to study medicine, but I did not pass the entrance test. · She was tired, so she went home early.
- You can pay online or at the desk. · He neither called nor wrote.
Subordinating conjunctions
Subordinating conjunctions begin a dependent clause, which cannot stand alone. They show reason (because, since, as), contrast (although, even though, while, whereas), time (when, after, before, until), and condition (if, unless, as long as).
The dependent clause can come before or after the main clause. If it comes first, add a comma: Although the weather was bad, the flight left on time. If it comes second, you usually do not need a comma: The flight left on time although the weather was bad.
Do not use two conjunctions to do one job. With although, do not add but. With because, do not add so. Say Because he was tired, he went home, and not Because he was tired, so he went home.
Correlative conjunctions
Correlative conjunctions work in pairs. The common ones are both ... and, either ... or, neither ... nor, not only ... but also, and whether ... or. The two parts must have the same grammatical form, which is called parallel structure.
For example, say She is both clever and hard-working (two adjectives), not She is both clever and works hard. Equally, say You can study either at home or abroad, where both parts are place phrases, rather than You can either study at home or abroad.
Verb agreement follows the nearer subject with either ... or and neither ... nor: Neither the manager nor the workers were told. With both ... and, the verb is plural. Whether ... or is useful for noun clauses: I have not decided whether to study in Leeds or in Bristol.
Conjunctions and linking adverbs
Words like however, therefore, moreover and consequently look like conjunctions, but they are not. They are linking adverbs, and they do not join two clauses on their own. If you put one between two clauses with only a comma, you create a comma splice: The prices rose, however, people still bought the product is wrong.
Fix it in one of three ways: use a full stop (The prices rose. However, people still bought the product.), use a semicolon (The prices rose; however, people still bought the product.), or use a true conjunction (The prices rose, but people still bought the product).
Mistakes to avoid
The most common mistakes are doubling conjunctions (Although ... but, Because ... so), joining two clauses with only a comma, and starting too many sentences with and or but in formal writing. Short sentences that begin with But are acceptable in speech, and they appear in some published writing, but they can look informal in an essay.
A second set of errors is using the wrong type of word after the conjunction. Although and because need a full clause with a subject and a verb. Despite and because of need a noun or an -ing form. Say Although it rained, we went out, or Despite the rain, we went out. Do not say Despite it rained.
Choosing the right conjunction
Before you choose a conjunction, name the relationship between the two ideas. Is the second idea an addition (and), a contrast (but, although), a reason (because), a result (so), a choice (or), or a condition (if)? Once you have named it, the conjunction is easy to choose.
Then check the structure. Some conjunctions are followed by a full clause (although, because, if, while). Others are followed by a noun or an -ing form (despite, because of, in spite of). If you mix them up, the sentence breaks, even if the meaning is clear.
Using conjunctions in IELTS
In Writing, conjunctions show range and control. A mix of coordinating and subordinating conjunctions makes your sentences varied and clear. In Speaking, and, but, so and because carry most of your sentences, and that is natural. Add although, while and if when you want to give a contrast or a condition. Aim for control first, and variety second.
Who finds this hard?
- Chinese speakers: Chinese often uses pairs of linking words together, as in although ... but, so learners add a second conjunction in English.
- Japanese speakers: Japanese joins clauses with verb endings and particles, so English conjunctions at the start of a clause take practice.
- Korean speakers: Korean joins clauses with endings on the verb, so learners may leave out the conjunction or put it in the wrong place.
- Arabic speakers: Arabic often links clauses with and, so learners write long chains of and instead of using a variety of conjunctions.
IELTS tip
In Writing Task 2, check each long sentence for one conjunction doing one job, and avoid pairs like although ... but and because ... so. In Speaking, use because and although to extend an answer with a reason or a contrast.
Frequently asked questions
What are the three types of conjunctions?
They are coordinating (and, but, so), subordinating (although, because, if) and correlative (both ... and, either ... or).
Can I start a sentence with and or but?
It is common in speech and acceptable in some writing, but in IELTS Writing it is safer to use a linking adverb or to join the sentences.
Is however a conjunction?
No. However is a linking adverb. Use a full stop or semicolon before it, not a comma.
Do I need a comma before and?
Use a comma before and when it joins two full clauses. Do not use one when it joins two words, two phrases or two verbs with the same subject.
Sources
- Swan, M. (2016). Practical English Usage (4th ed.). Oxford University Press.
- Carter, R. and McCarthy, M. (2006). Cambridge Grammar of English. Cambridge University Press.