Co-ordination

last changed 24 June 2003


What is co-ordination?

Co-ordination is a very basic grammatical relationship which is generally easy for KS3 pupils to use both in speech and writing. However they should understand where it is appropriate and where not, and be aware of the few common pitfalls.

It is the use of a very small number of words like and to link grammatical units in sentences. It is one of the most basic grammatical patterns. Here is an example of co-ordination in KS3 writing:

Sadie and I just looked at each other and looked back into the clearing.

The co-ordinating conjunctions are highlighted, and the underlining shows the units that they co-ordinate.

Co-ordination links units that have the same relationship to the rest of the sentence. It is a basic grammatical relationship, which contrasts with the relationship between a modifier and its head. In co-ordination the units are equal, whereas in modification they are unequal. For example, in lion trainer, the first noun modifies the second, so their relationship is unequal, whereas in lion and trainer the two nouns are equal.

What this 'equality' means is this:

Both of the co-ordinated units must have the same relationship to the rest of the sentence.

For example:

a lion and trainer performance

Here the words lion and trainer jointly modify the word performance, giving the meaning:

a performance which involves both a lion and a trainer.

This contrasts with:

a lion trainer performance

where the word lion modifies trainer, which in turn modifies performance:

a performance by a lion trainer (a trainer of lions).

The contrast can be shown easily using diagrams, which is a useful way of demonstrating the idea to pupils.

The same principle applies to much more complicated structures. For example, if two clauses are co-ordinated, they may have the same relationship to a noun phrase which acts as the subject in each of them:

Or indeed, they may share the fact that neither of them has any grammatical relationship at all to the rest of the sentence:

The sun came out and we started to feel warm.

What kind of units can be co-ordinated?

Co-ordinating conjunctions can link grammatical units of almost any size:

  • single words:
  • I ate all the apples and oranges

  • phrases:
  • I ate all the apples and half of the oranges

  • clauses:

    I ate all the apples and she ate all the oranges

They can link even

  • morphemes:
  • pre- and post-modifiers

  • whole sentences:

    He had to mark 30 essays and 50 exam scripts. And that was just for English.

They can also link words (or phrases) of almost any class:

  • nouns:

    The apples and pears were all ripe.

  • verbs:

We grow and eat our own vegetables.

  • adjectives:

The café was cheap and nasty.

  • adverbs:

They answered clearly and accurately.

  • prepositions:

There are birds inside and outside the barn.

  • pronouns:
  • You and I could go together.

  • determiners:

    Do you prefer this or that colour?

How does simple ellipsis work in co-ordination?

Ellipsis is the term we use when words or phrases are left out to achieve a more compact expression. Co-ordinating conjunctions allow elements to be omitted from later units when they would duplicate elements in the first one. For example, if two clauses are co-ordinated, they may both share the same subject, so this subject may be omitted in the second clause to avoid repetition:

may be shortened to:

Similarly, a shared auxiliary verb (or string of auxiliaries) or an adverb may be omitted from the second clause, so:

I have often gone to the library and I have often fallen asleep.

may be reduced to:

I have often gone to the library and fallen asleep.

In some cases this reduction is demanded by the meaning. For example, it is possible to say:

I have often gone to the library and I have often fallen asleep, but I have never gone to the library and fallen asleep.

If we are thinking of "going to the library and falling asleep" as a single event, we have to omit I have from the second clause.

The same kind of ellipsis is possible wherever co-ordination is found; for example, the noun phrases:

my favourite French wine and my favourite German beer

may be shortened to:

my favourite French wine and German beer

This kind of ellipsis is simple because it simply shortens the second unit by removing material from the beginning. It is easy to see this if we write the co-ordinated units one above the other:

my favourite French wine and

my favourite German beer

I have often gone to the library and

I have often fallen asleep.

How can we distinguish co-ordination from subordination?

Simple ellipsis is a distinctive characteristic of co-ordination, and distinguishes co-ordination rather clearly from subordination. For example, if we start with a pair of clauses linked by a subordinating conjunction such as because:

They went to bed early because they were tired.

we cannot shorten it by omitting the duplicated words:

They went to bed early because they were tired.

The possibility of ellipsis is a useful test for co-ordination, which picks out a small list of co-ordinating conjunctions.

The basic difference between co-ordination and subordination is that co-ordination links equals. This means that co-ordinated items have to be balanced, which sometimes raises problems in KS3 writing. It is important to know how co-ordinated items should match.

How is co-ordination signalled by punctuation?

In simple cases, a co-ordination has the following pattern of punctuation:

... , ... , ... and ...

For example:

We've studied astronomy, archaeology, algebra and art.

We went out, looked around a bit, had a swim and went home.

Every KS3 pupil should be able to use this pattern, but they should also be encouraged to explore more ambitious patterns in which commas are replaced by 'heavier' punctuation marks - semi-colons or even full stops, which would have improved the following KS3 example:

Last night we heard some kind of growl but we thought nothing of it and went to sleep. But today we have found large foot-prints.

For more on punctuation in co-ordination, go to Sentence-level punctuation.

Advanced uses of co-ordination

Three kinds of co-ordination generally develop later and can be very effective when used well:

  • Co-ordination without a conjunction (e.g. I came, I saw, I conquered.)
  • Complex ellipsis (e.g. Some prefer coffee and others, tea.)
  • Paired conjunctions (e.g. He both attended the concert and bought a programme.)

 

What are the co-ordinating conjunctions?

The best test for co-ordinating conjunctions is the ellipsis test.

The words that pass this test are:

  • and - I have been working hard and learning a lot.
  • but - I have been working hard but not learning much.

Beware of the preposition but which means 'except' - Everyone but John passed.

  • or - I have been working hard or playing games.
  • nor - I have been neither working hard nor playing games.

Not to be confused with the adverb nor which contrasts with so, as in No, nor do I. The conjunction is always paired with neither.

  • then - I have been working hard then playing games.

The conjunction is rather hard to distinguish from the adverb then, as in:

    ... and then we went home

    We then went home.

  • yet I have been working hard yet not learning much.

The conjunction is again hard to distinguish from the adverb yet, as in ... and yet he meant well; not to be confused with the adverb yet meaning 'until now', as in Have you done your homework yet?

All of these words except the conjunctions nor and yet are very common in KS3 speech.


How must co-ordinated units match?

Co-ordinated items must be grammatically matched, both in terms of their grammatical class and in terms of the ellipsis described above.

For example, we can co-ordinate

thunder and lightning

when both are nouns:

We had thunder and lightning.

This is grammatical: noun + noun which are both the object of had.

But the sentence is not grammatical when thunder is a verb: for example

It will probably thunder and lightning.

The reason for this ungrammaticality is very simple. If two units are co-ordinated, they both have the same grammatical relationship to the rest of the sentence. This is what co-ordination means. Therefore they must both be suited to this relationship; if it demands a noun phrase, they must both be noun phrases, if it demands an infinitive, they must both be infinitives, and so on.

This principle is not always easy to apply because the ideas that a writer (or speaker) wants to co-ordinate may require incompatible wording. The result is an unmatched list.

Here is a KS3 example which illustrates the matching problems of a co-ordinated list:

You can go fishing, crabing, and even go in a dingie on the water.

The problem here is that the first two co-ordinated units are both related to go:

go fishing

go crabing

whereas the third is related to can:

can go fishing

can go crabing

can go in a dingie

You can go fishing, crabing, and even go in a dingie on the water.

Putting it another way, for the first two co-ordinated units the word go (in go fishing) is not part of the list of 'things to do', whereas for the third unit it is.

A helpful way to check a co-ordinated list for matching is to write the co-ordinated units one above the other. If the units match it should be possible to combine each one separately with the rest of the sentence (shown by the ditto marks). For example,

You can go fishing,

crabbing and

sailing in a dinghy on the water.

can be expanded to:

You can go fishing,

you can go crabbing, and

you can go sailing in a dinghy on the water.

In contrast, the unmatched list cannot be expanded in this way:

You can go fishing,

you can go crabbing, and

you can go go in a dinghy on the water.

Learning to match items in a list is a good way to learn to pay attention to sentence structure.


Co-ordination without a conjunction

In general, co-ordination needs to be signalled by a conjunction.

Weaker writers should be encouraged to follow this principle in order to avoid 'comma splices', which are clauses linked simply by a comma as in the following KS3 example:

I couldn't bare it anymore I just ran into the house shaking all over, I was sweating so much the it was dripping of me.

This sentence consists of three clauses that are simply juxtaposed, without even a comma between the first two. One way to improve it is to turn it into a regular co-ordination in which the second and third clauses are co-ordinated with each other and then with the first. This requires the addition of two co-ordinating conjunctions:

I couldn't bear it anymore so I just ran into the house shaking all over and I was sweating so much that it was dripping of me.

What this writer needs is a clear understanding of the general principle that clauses cannot simply be put next to each other to make a sentence.

However, once this principle is established writers should explore the possibilities of co-ordination without conjunctions. This can be effective when the intention is to give a short list of examples without covering all possibilities. This is presumably the aim of the following KS3 letter (to a friend):

I was there with a few mates, you know doing the usual sort of things, scaring old ladies, engraving a few names on the park bench.

If and or or had been used here, it might have implied that these two activities were the only options, whereas the conjunction-free list implies that it could have been continued.

Complex ellipsis.

In simple ellipsis, the duplicated words which are omitted would have been on the edge of the second unit. In more complex ellipsis, it is possible to omit duplicated material from the middle of this unit. For example:

  • Simple ellipsis:

The children decided to play rounders and

the children had a lot of fun.

  • Complex ellipsis:

    The children decided to play rounders and

    the adults decided to play cricket.

This pattern is one that more ambitious KS3 pupils should be able to use for the sake of its economy and elegant parallel structure.

Paired conjunctions

Some conjunctions can be paired with an earlier word which signals the start of the co-ordinated pattern. For example, and may be paired with both:

Some people both take a lot of exercise and drink too much.

Here is a full list of the paired conjunctions:

  • both and

Not to be confused with the determiner or pronoun both, as in:

Both her parents are dead.

I'll take both of them.

  • not only but
  • either or

Not to be confused with the determiner or pronoun either, as in:

Either book will do.

  • neither nor.

Not to be confused with the determiner or pronoun neither, as in:

Neither of them did it.

Such paired co-ordinating conjunctions help the reader or hearer by signalling the start of a co-ordination pattern: once we read (or hear) either, we know to expect or - as in the example by Groucho Marx:

Either this man is dead or my watch has stopped.

A paired conjunction may also help to reduce ambiguity. For example,

We stock food for animals and fish.

could mean either

We stock food for animals and fish.

or

We stock food for animals and fish.

We can remove this ambiguity by placing both just before the first co-ordinated unit:

We stock both food for animals and fish.

We stock food for both animals and fish.