What are compound sentences?

A compound sentence is a sentence with two clauses.

A clause is a part of a sentence or a group of words which have a ‘subject’ and an action or ‘verb. The subject is the person/thing

that does the action.

So:

“John works” is a clause with a ‘subject’ i.e. John and a verb i.e. an action which is ‘works’.

Let’s see another clause.

“Peter relaxes”.

Here ‘Peter’ is the subject i.e. the person who is doing the action or ‘verb’. The verb or action here is ‘relaxes’.

Both of these clauses are called ‘independent clauses’ because they could be by themselves and still have some meaning and are not incomplete.

Another example of an ‘independent clause’ is ‘John does the washing’.

‘John does the washing’ by itself has some meaning and can be a separate or ‘independent’ sentence or clause.

But if we said ‘John does the’, this would be incomplete because we don’t know what John ‘does’ and this would not be an independent clause.

Coordinators

We could leave the two clauses above as two separate sentences. ‘John works. Peter relaxes.’

Or we could join them together and make one sentence.

To join them we connect them with little words called ‘coordinators’, such as ‘and’ or ‘but’.

So we could say ‘John works but Peter relaxes.’

This sentence is a compound sentence because it has two clauses each of which has a subject (John and Peter) and a verb (works and relaxes) and are joined together by a ‘coordinator’ which is ‘but’.

The seven coordinators are:

For—And—Nor—But—Or—Yet—So

‘For’, ‘And’, ‘Nor’, ‘But’, ‘Or’, ‘Yet’ and ‘So’.

Sometimes however we join independent clauses with a semi-colon.

We remove the ‘coordinator

So for example if we said:
“I met David and he was wearing a blue shirt.”

We would remove the ‘coordinator’ and make the sentence.

“I met David; he was wearing a blue shirt.”

The second clause must be closely related to the first clause.

Example: “It was very; I didn’t eat it.”

Normally we would say “It was very hot, so I didn’t eat it.”

But if we remove ‘so’ we can use a semi-colon because the two things are so closely related to each other they can be put in one sentence.

Conjunctive adverbs.

We can also join independent clauses with ‘conjunctive adverbs’.

After the first clause we must have a semi-colon, then the ‘conjunctive adverb’ and then a comma and then the second clause.

So, 1. first clause 2. semi-colon 3. conjunctive adverb. 4. comma and 5. second clause.

Examples:
“Peter studied hard; however, Martin is very lazy.”

“Susan was driving to work; meanwhile, John was shopping.”

Here are some examples of compound sentences with a coordinator, remember ‘FANBOYS’ (For, And, Nor, But, Or, Yet, So)

1. I cannot take this, for John would be angry with me.
2. He was very rude, and he still hasn’t apologised!
3. I don’t like liars, nor does Katie.
4. I would help you, but I am help my sister on Saturdays.
5. You could go to the library, or you could go to the cafe.
6. He studied very hard, yet he didn’t pass.
7. We wanted to get there early, so we took the train.

Some examples with semi-colons:

1. I only studied French in school; I never studied Spanish there.
2. Phone me on Monday; I  should have the book for you on that day.
3. I always study in the library; it’s so peaceful.
4. They spent a lot of money on their new kitchen, it looks very new.
5. They are very happy with Tim; they may give him more money!
6. My computer wasn’t working; there was a problem with the screen.
7. He is very good in football; he is ranked no.1 in his class.

Some examples with conjunctive adverbs:

1. I must do my homework; otherwise, I will get punished.
2. He is very clever; however, he never gets good exam results.
3. He can play football and tennis; in addition, he can swim.
4. I don’t like studying; nevertheless, I have to do it to get a good result.
5. Jason always watches movies; in comparison, Tom always plays video games.
6. I didn’t buy her latest book; besides, I heard it’t not very good.
7. He is sick today; hence, he is not in.