Sentence Structure 2: Compound Sentences


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Sentence Structure 2: Compound Sentences

Students studying

Students studying © ELT, University of St Andrews


Clauses are the building blocks of sentences. Understanding how to combine clauses accurately within sentences will allow you to express your thoughts more precisely in writing.


In this lesson, you will examine three methods of combining clauses.

1. With a coordinator: I play golf well, but I’m terrible at squash.

2. With a conjunctive adverb: I play golf well; however, I’m terrible at squash.

3. With a semi-colon: I play golf well; I’m terrible at squash.

You will also study each method’s correct punctuation.

This lesson is the second in a series designed to help you understand the different types of sentences in English.



Activity 1: Which words are coordinators?

A compound sentence made with a coordinator has the following structure:

Independent clause + comma +coordinator + independent clause.

  e.g.     I play golf well,              but                 I’m terrible at squash.



Check each sentence which contains a coordinator.

Additional Resources

Download a summary of coordinators (pdf 44 KB)

Activity 2: Using coordinators

There are seven coordinators in English. These are sometimes known as FANBOYS words:

F  for

A  and

N  nor

B but

O  or

Y  yet

S  so


Combine each pair of independent clauses below to make a compound sentence, using the most suitable coordinator for the meaning. Use each coordinator once. Remember to punctuate the sentences correctly.

Activity 3: Using Conjunctive Adverbs

In the first two activities, you practised using coordinators to join independent clauses. The following activity moves on to another way of making compound sentences: conjunctive adverbs.

A compound sentence made with a conjunctive adverb is made as follows:

Independent clause + semi-colon + conjunctive adverb + comma + independent clause

E.g.      I play golf well;                                       however,                  I'm terrible at squash.





Read the sentences carefully and select the correct word from the drop-down list.

1. You should register with a doctor as soon as possible;........., you may have problems accessing medical services in the UK.

2. Scotland is the home of golf; ........................., it is a popular holiday destination with golf lovers.

3. St Andrews is a university town; ....................., it is a very safe place to live.

4. IELSS offers workshops in many different aspects of English; ....................., it provides one-to-one tutorials so that students can receive individualised tuition.

5. The special relationship between Scotland and America dates back many centuries; ................, Scotland is a popular tourist destination with many Americans.

6. St Andrews has two supermarkets; ......................., it has many smaller, independent food shops.

Additional Resources

Download an overview of conjunctive adverbs and coordinators (pdf 28 KB).

Activity 4: Joining clauses with semi-colons

The third way of forming compound sentences is with semi-colons. Sentences joined in this way have the following form:

Independent clause + semi-colon + independent clause

e.g. Examinations cause some students to panic; others find that examinations motivate them to study.

Notice that the two clauses are on the same topic (examinations), but the logical link between the two ideas is not explicit. Also, as both clauses are independent, they could have been separated by a full-stop: Examinations cause some students to panic. Others find that examinations motivate them to study.


Decide whether the following sentences use the semi-colon correctly.

Activity 5: Progress Check


Now put all your skills into practice. Look at the following compound sentences and decide whether they are correct.

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1. Prices rose rapidly, consequently demand fell.

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2. Prices rose, so demand fell.

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3. Women tend to have healthy diets; otherwise, they are healthy.

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4. The book is fascinating; a ghost story of St Andrews.

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5. East Sands Beach is beautiful, however it can be a little windy there in the winter.

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6. Yoga provides a great physical workout; furthermore, it is a good form of relaxation.

Additional Resources

Further practice

Download the extension activities (33 KB). If you would like feedback on these, bring them to an IELSS tutorial.


© Janie Brooks / University of St Andrews/ Creative Commons: Attribution Non-Commercial Share Alike 2011

Created using the LOC Tool, University of Southampton