UCL English


Punctuation Guide

This guide aims to explain the basic rules of punctuation, and to help undergraduates to avoid some of the most common errors. It is intended as a rapid reference tool and is by no means exhaustive.

For more detailed explanations students are advised to look at Fowler’s Modern English Usage.

Independent and dependent clauses








Brackets (parentheses)




Punctuation Exercises

Independent and Dependent Clauses

The ability to identify independent and dependent clauses is an important part of understanding how to punctuate your sentences correctly (particularly in the cases of the comma and the semicolon).

An independent (or main) clause contains a subject and verb, and forms a complete meaning in itself (i.e., it could stand alone as a complete sentence).

A dependent (or subordinate) clause does not form a complete meaning and cannot stand alone; it needs an independent clause to complete its meaning.


In the following sentences, the independent clause or clauses are marked [i] while dependent clauses are marked [d]:

‘The gardener had been up since dawn [i], mowing the lawns and sweeping them [d 1], until the grass and the dark flat rosettes where the daisy plants had been seemed to shine [d 2].’

Katherine Mansfield, ‘The Garden Party’ (1922) in The Collected Stories (London: Penguin, 2001), 245.

‘Although there is little explicit reference to Elizabeth in Shakespeare’s works [d], over a long period scholars have sought her there in veiled or encoded forms [i].’

Helen Hackett, Shakespeare and Elizabeth: The Meeting of Two Myths (Princeton: Princeton University Press, 2009), 112.

‘One very sunny afternoon Sophie went inside for her piano lesson [i 1], and Mary remained seated on the grass [i 2].’

Jane Bowles, Two Serious Ladies (1943; London: Virago, 1979), 5.

Note: In many instances, such as the second example from Helen Hackett, it is the subordinating conjunction that makes the clause subordinate, or dependent (i.e., if this word was taken away the clause would be independent). On the other hand, coordinating conjunctions (as in the last example from Jane Bowles), and conjunctive adverbs (however, therefore, etc.), do not make independent clauses dependent.

Clauses Exercise


As their name suggests, conjunctions are used to connect words and phrases.

Coordinating Conjunctions

Coordinating conjunctions can be used to join individual words (‘pen and paper’). They can also connect independent clauses:

‘The doors stood open, breathing out incense and heavy soul, and the spirit was that of the market scene in the pantomime when the cast, encouraged by the audience, has let the business get out of hand.’

Penelope Fitzgerald, Offshore (1979; London: Flamingo, 2003), 148.

‘She loved not the savour of tar nor of pitch,
Yet a tailor might scratch her where'er she did itch.’

William Shakespeare, The Tempest (1611; London: Arden Shakespeare, 2001), 2.2.51-2.


List of coordinating conjunctions:










Subordinating Conjunctions

As their name suggests, these can connect subordinate (or dependent) clauses to an independent clause.


‘she never showed fatigue, except fatigue of the eyes.’
Elizabeth Bowen, Death of the Heart (1938; New York: Anchor Books, 2000), 26.

Though uncertain that any one were to blame, she found fault with every absent friend.’
Jane Austen, Sense and Sensibility (1811; London: Penguin, 2003), 333.

‘She was in revolt, until a whisper of the day of bells reduced her to blank submission.’
George Meredith, The Egoist (1879; London: Penguin, 1968), 134.

Note: In many instances (such as the last example) it is the subordinating conjunction that makes the clause subordinate or dependent (i.e., if this word were taken away the clause would be independent). This is not the case with coordinating conjunctions or conjunctive adverbs.

There are many subordinating conjunctions, but here are some common ones, grouped according to the relations that they express:

  • Time (after, before, as, since, until, when, whenever, while)
  • Place (where, wherever)
  • Purpose (to, in order to, so that)
  • Reason (because, since, for)
  • Exception (except, save that)
  • Contrast (whereas, whilst, while, although, though)
  • Condition (if, unless, in case, as long as)

Conjunctive Adverbs

A conjunctive adverb indicates the relationship between two independent clauses. It differs from other types of conjunctions in three important ways:

  • It can often be moved to other parts of the clause:

However, he thought that he would get away with it’.

‘He thought, however, that he would get away with it’.

  • If it is placed at the beginning of an independent clause, it must be preceded by a semicolon or full stop, not a comma:

‘He knew that what he did was wrong; nevertheless, he felt no remorse’.

  • In almost all cases, a conjunctive adverb should be followed by a comma.

Some common conjunctive adverbs:











Please be aware that this is simply a checklist. It is aimed at helping one avoid the most common errors that are made when using commas and is by no means exhaustive. For a more thorough explanation of commas please refer to Fowler’s Modern English Usage.


Listing Commas

The listing comma is used to separate words, phrases or clauses in a list, especially where one could use and or or instead.


‘The poet’s mind is in fact a receptacle for seizing and storing up numberless feelings, phrases, images, which remain there until all the particles which can unite to form a new compound are present together.’

T.S. Eliot, 'Tradition and the Individual Talent' (1919) in Selected Prose of T.S. Eliot (London: Faber and Faber, 1975), 41.

‘Neary besieged Miss Counihan with attentions, sending her mangoes, orchids, Cuban cigarettes and a passionately autographed copy of his tractate, The Doctrine of the Limit.’

Samuel Beckett, Murphy (1938; London: Faber and Faber, 2009), 34.

(Please note that some writers would place a comma before the and at the end of a list. This is sometimes called the ‘Oxford Comma’ and is not compulsory.)

Joining Commas

The joining comma is used where two independent clauses are joined to form one sentence. It must, however, precede the following coordinating conjunctions: and, or, but, while and yet.


‘He must be quite aware of the obvious fact that art never improves, but that the material of art is never quite the same.’

T.S. Eliot, 'Tradition and the Individual Talent' (1919), 39.

‘That is I write books but I am not proud of this any more than anyone is of their nails growing, and if it be argued that I was happier at this period because I had less free time than most you will be wrong’.

Henry Green, Pack my Bag (1940; London: Vintage, 2000), 154.

Be aware that there are also conjunctive adverbs which should not follow a joining comma, e.g. therefore, however, consequently, moreover, nevertheless, meanwhile, thus etc. In the latter cases, and in cases where no conjunctions are present, a semicolon or a full stop should be used.

Here’s an example where a semicolon is required; to use a comma here would be wrong and is known as a comma splice:

‘That, none the less, was but a flicker; what made the real difference, as I have hinted, was his mute passage with Maggie.’

Henry James, The Golden Bowl (1904; London: Penguin, 2001), 148.

Bracketing Commas

Bracketing commas are used to bracket off weak interruptions: insertions, asides or afterthoughts. (Dashes or brackets may also be used for this.) Check carefully that the bracketed words are really an interruption; it is only non-restrictive (or non-defining) relative clauses which require bracketing commas. In these cases the non-restrictive clause, which is bracketed by commas, could be removed without destroying the sense.


‘The anxiety, it was true, would have been, even though not imparted, separately shared; for Fanny Assingham’s face was, by the same stroke, not at all thickly veiled for him, and a queer light, of a colour quite to match, fairly glittered in the four fine eyes of Miss Lutches.’

Henry James, The Golden Bowl, 148.

‘His soul swooned slowly as he heard the snow falling faintly through the universe and faintly falling, like the descent of their last end, upon all the living and the dead.’

James Joyce, ‘The Dead’ in Dubliners (1914; London: Granada Publishing, 1979), 201.

Tips and Advice

  • Beware the comma splice. Do not use a comma to separate two independent clauses that are not linked by a conjunction; this is the role of the semicolon or the full stop.
  • The decision on whether to use a comma that is not absolutely essential is a matter of individual style. Just be aware that overuse can lead to cluttered or stuttering prose, whereas underuse can make prose more difficult for the reader to follow.

Comma Exercise

The Dash

Since the dash has several uses, each has been given a name to make it easier to distinguish between them.

Bracketing Dashes

Like brackets and bracketing commas, this set of two dashes is used to bracket off weak interruptions: insertions, asides or afterthoughts. Bracketing dashes should only be used if the words enclosed within the two dashes are not grammatically or semantically essential to the sentence (i.e., if they were removed the sentence would still make sense).


‘Most of them clearly – or, in many cases, fuzzily – depicted life in the field.’

Alan Hollinghurst, The Swimming-Pool Library (1988; London: Vintage, 1998), 95.

‘I stood up on the daybed – my finger still holding my place in the book – and, stretching to my full height, tried to make out what was being said up there and by whom.’

Philip Roth, The Ghost Writer (New York: Vintage International, 1979), 116.

In the second example, the interruption is like the finger in the book it describes: one allows Roth to keep hold of two ideas in the same sentence; the other allows his character to keep his place in a book whilst performing an awkward eavesdropping manoeuvre.

Note: Bracketing dashes tend not to detract from the importance or relevance of the enclosed material as much as brackets.

The Afterthought Dash

A single dash may be used before an afterthought that occurs at the end of a sentence:

‘A London society lady gives her views on not spoiling the servants by lending them books “of the wrong kind for their station” and making them dissatisfied – “and dreadfully ambitious!” suggests Ethelberta slyly.’

Claire Tomalin, Thomas Hardy: The Time-Torn Man (London: Viking, 2006), 150

The Explanatory Dash


This dash is used to introduce examples, explanations, elaborations or amplifications:


‘...there were odd items tucked between the pages – postcards, letters, drawings, even hotel bills and visiting cards.’

Alan Hollinghurst, The Swimming-Pool Library, 95.

‘What he writes is based on ideas independently formed – both generated and shaped by himself, without either confirmation, challenge, or complication from relevant reading.’

Rachel Bowlby, Freudian Mythologies: Greek Tragedy and Modern Identities (Oxford: Oxford University Press, 2007), 30.

‘Carlyle told Chapman in March that he had received a letter from Dr Stamm announcing that he intended to call on him – a letter which made Carlyle expect “nothing less than Elijah the Tishbite”, as Marian reported to the Brays.’

Rosemary Ashton, 142 Strand (London: Chatto & Windus, 2006), 177.

Note: These dashes are doing a similar job to that of the colon, but they tend to be less formal. They can also be less obstructive to the flow of the sentence.


Tips and advice:


  • One advantage of the dash is that it can help to narrow the gap between writing and thought processes. By the same token, it can make prose seem more natural or conversational. However, excessive or inappropriate use of the dash can make writing seem informal and/or under-considered.

Brackets (parentheses)


Brackets introduce or set off a strong or weak interruption (asides, afterthoughts, sudden interjections, etc.): something that has a bearing on the context of the sentence, but in a purely subordinate way (i.e., if it were lifted out the sentence would still be grammatically correct).


‘What we call happiness in the strictest sense comes from the (preferably sudden) satisfaction of needs which have been dammed up to a high degree.’

Sigmund Freud, 'Civilization and Its Discontents' (1930), The Standard Edition, vol. 21 (London: The Hogarth Press, 1995), 76.

‘The evil of the actual disparity in their ages (and Mr Woodhouse had not married early) was much increased by his constitution and habits;’

Jane Austen, Emma (1815; Cambridge: Cambridge University Press, 2005), 5.

Brackets are often used for enclosing additional information and can carry the meaning of ‘i.e.’ or ‘namely’.


‘…his Osenbrigs (a sort of brown Holland suit he had on) cou’d not conceal the Graces of his Looks and Mien;’

Aphra Behn, Oroonoko; or, The Royal Slave (1688; Boston, MA: Bedford/St. Martin’s Press, 2000), 68.

Tips and Advice

  • If brackets are used within a sentence then the full stop should come outside of the second bracket. (If the whole sentence is within the bracket, then it should remain inside.)



Joining Related Independent Clauses

Semicolons are used to join two or more related independent clauses without linking words (conjunctions).


‘Dickens exaggerates and generalizes; Emily Brontë focuses and substantiates the passions.’

Barbara Hardy, Forms of feeling in Victorian Fiction (1985; London: Methuen, 1986), 97.

‘Yet this capital was by no means sufficient to let the family live on the interest of it; for one year, perhaps, or at the most two, they could live on the principal, that was all.’

Franz Kafka, ‘The Metamorphosis’ (1915) in Kafka’s ‘The Metamorphosis’ and Other Writings, trans. Volkmar Sander and Daniel Theisen (London: Continuum, 2002), 22.

‘The shadows on the perfect lawn were straight and angular; they were the shadows of an old man sitting in a deep wicker-chair near the low table on which the tea had been served, and of two younger men strolling to and fro, in desultory talk, in front of him.’

Henry James, The Portrait of a Lady (1881; London: Penguin, 2003), 59.

One of the beauties of the semicolon is that it can allow the writer to imply a relationship between two clauses without explicitly specifying this relationship. This can make for more suggestive prose; it can also encourage more active interpretation on the part of the reader.

Complex Lists

Semicolons are often used to separate terms in a list, particularly when these individual terms contain commas.


‘…these years have seen the reprinting of her novels, which matters; the publication of a Penguin Selected Poems, and of an excellent selection of poetry and prose (by Hermione Lee), which matters more; and the publication of the Collected Poems, which matters most.’

Christopher Ricks, ‘Stevie Smith’ in The Force of Poetry (1984; Oxford: Oxford University Press, 2002), 255.

‘[Pindar’s] complex stanzas were patterned in sets of three: moving in a dance rhythm to the left, the chorus chanted the strophe; moving to the right, the antistrophe; then, standing still, the epode.'

M. H. Abrams, A Glossary of Literary Terms, 7 th Edition (London: Harcourt Brace, 1999), 198.

‘In people's eyes, in the swing, tramp, and trudge; in the bellow and the uproar; the carriages, motor cars, omnibuses, vans, sandwich men shuffling and swinging; brass bands; barrel organs; in the triumph and the jingle and the strange high singing of some aeroplane overhead was what she loved; life; London; this moment of June.’

Virginia Woolf, Mrs Dalloway (1925; Oxford: Oxford University Press, 2000), 4.

Preceding Conjunctive Adverbs (however, nevertheless, etc)

Semicolons are used to join independent clauses together with the following conjunctive adverbs: therefore, however, consequently, moreover, otherwise, nevertheless, meanwhile, thus etc.


‘In the event, Donne recovered from the sickness that precipitated “Hymne to God my God, in my sicknesse”; nevertheless, the poem arises from his conviction that he is in the last moments of life about to enter the precincts of death.’

Helen Vendler, Last Looks, Last Books: Stevens, Plath, Lowell, Bishop, Merrill (Princeton: Princeton University Press, 2010), 14.

‘A system of hypocrisy, which lasts through whole years, is one seldom satisfactorily practised by a person of one-and-twenty; however, our readers will recollect, that, though young in years, our heroine was old in life and experience, and we have written to no purpose if they have not discovered that she was a very clever woman.’

William Makepeace Thackeray, Vanity Fair (1848; Oxford: Oxford University Press, 1998), 111.

Preceding Coordinating Conjunctions (and, but, etc)

Semicolons can be used to separate two independent clauses with a coordinating conjunction (and, but, yet, or, then, so). As with complex lists, this is particularly helpful when there are already a lot of commas in the sentence.


‘In their memories of nursery rhyme and of fairy tale, in their lisping and lilting, they are a child’s eye view; yet children don’t write poems which matter except as that diminished thing, poems-by-children.’

Christopher Ricks, ‘Stevie Smith’, 247.

Common Misuses

  • Using a semicolon to join two clauses when one of these is not independent.


‘Dickens created many brilliant comic characters, but Mrs Gamp makes me laugh the most; more, even, than cushion-throwing Grandfather Smallweed.’

  • Using a semicolon where a colon would have been more appropriate.


‘There is one thing you must remember about semicolons and colons; the two are not interchangeable.’

Here the special conditions which necessitate the use of a colon are present: a premise or introductory statement followed by an answer.


You will probably come across examples of authors who break these rules. This is often a result of changes in grammatical conventions over time.


‘…while engaged in this survey she had made room in it for her companions; a comprehensiveness of observation easily conceivable on the part of a young woman who was evidently both intelligent and excited.’

Henry James, The Portrait of a Lady, 72.

‘“Yes,” said she; adding to herself: “Rather mild!”’
Thomas Hardy, Jude the Obscure (1895; London: Penguin, 1998), 47.

Tips and Advice:

  • As with most punctuation marks, it is best not to overuse the semicolon.

Semicolon Exercise


The Colon of Introduction

Colons are used to introduce a list, a quotation or a speech.


‘This is conventionally agreed to be true of written language, but Derrida argues that it is just as much the condition of spoken language:

Every sign, linguistic or non-linguistic, spoken or written (in the usual sense of this opposition), as a small or large unity, can be cited, put between quotation marks; thereby it can break with every given context, and engender infinitely new contexts in an absolutely nonsaturable fashion.’

Steven Connor, Samuel Beckett: Repetition, Theory and Text (1988; Aurora, CO: The Davies Group, 2007), 142.

‘I looked at him for only a second; a phrase from the Firbank I had just been reading came back to me: “Très gutter, ma’am”’.

Alan Hollinghurst, The Swimming-Pool Library, 170.

The Colon of Explanation

Colons point forward to an explanation or elaboration of what has come before.


‘It is just as with living creatures: when soul and body come together and remain united, we speak of a living being, but when this unity breaks up through the separation of either component, it is clear that the living being perishes and no longer exists.’

Boethius, The Consolation of Philosophy (c. 524; London: Penguin, 1969), 105-6.

‘[Pindar’s] complex stanzas were patterned in sets of three: moving in a dance rhythm to the left, the chorus chanted the strophe; moving to the right, the antistrophe; then, standing still, the epode’

M.H. Abrams, A Glossary of Literary Terms, 198.


Punctuation Exercises

Independent and Dependent Clauses Exercise

Identify the independent and dependent clauses in the following sentences. If there is more than one of either type of clause in a sentence, label them i1, i2 etc., or d1, d2 etc.

  • ‘Next day the light of the October morning was falling in dusty shafts through the uncurtained windows, and the hum of traffic rose from the street.’

Virginia Woolf, A Room of One’s Own (1929) in A Room of One’s Own/Three Guineas, ed. Michèle Barrett (London: Penguin, 1993), 86.

  • ‘When he saw it he drew back, and his cheeks flushed for a moment with pleasure.’

Oscar Wilde, A Picture of Dorian Gray (1891; London: Penguin, 2000), 27.

  • ‘Railway termini gave us weepy farewells and course recouplings.’

Julian Barnes, Metroland (1980; London: Vintage, 2009), 29.

  • ‘While Christophine scrubbed my face and tied my plaits with a fresh piece of string, she told me that those were the new people at Nelson’s Rest.’

Jean Rhys, Wide Sargasso Sea (1966; London: Penguin, 1997), 11.

  • ‘At a students’ eating-house, they found an American girl who seemed to remember Robert; at least, he was called Robert and fitted the description.’

Muriel Spark, Territorial Rights (1979; London: Penguin, 1991), 128.

  • ‘There is something more, if I could find a name for it.’

Robert Louis Stevenson, The Strange Case of Dr Jekyll and Mr Hyde (1886; London: Penguin, 2003), 16.

Click here to see answers.


Comma Exercise

Can you specify which types of commas (Listing, Joining or Bracketing) are being used in these examples?

  • ‘To write the Life of him who excelled all mankind in writing the lives of others, and who, whether we consider his extraordinary endowments, or his various works, has been equalled by few in any age, is an arduous, and may be reckoned in me a presumptuous task.’

James Boswell, Boswell’s Life of Johnson (1791), ed. George Birkbeck Hill, vol. I (Oxford: Clarendon Press, 1934), 25.

  • ‘Here you are barricading yourself in your room, giving only yes or no for an answer, causing your parents a great deal of unnecessary anxiety, and besides – I merely mention this in passing –neglecting your duties towards the firm in a positively outrageous manner.’

Franz Kafka, ‘Metamorphosis’ (1915) in Metamorphosis and Other Stories, trans. and ed. Malcolm Pasley (London: Penguin, 2000), 83-4.

  • ‘It is impossible to escape the impression that people commonly use false standards of measurement – that they seek power, success and wealth for themselves and admire them in others, and that they underestimate what is of true value in life.’

Sigmund Freud, ‘Civilization and Its Discontents’ (1930) in The Standard Edition, vol. 21 (London: The Hogarth Press, 1995), 64.

  • ‘Romance, which expresses the desire to escape from real life, was suffering eclipse, or rather, perhaps, running into new moulds; the novel, which represents an acceptance of real life, was being born.’

Arundell Esdaile, A List of English Tales and Prose Romances Printed Before 1740 (New York: Burt Franklin, 1971), xxi.

  • ‘The Olivers, who had bought the place something over a century ago, had no connection with the Warings, the Elveys, the Mannerings or the Burnets;’

Virginia Woolf, Between the Acts (1941), ed. Gillian Beer (London: Penguin, 1992), 7.

Click here to see answers.


Semicolon Exercise

Which of the following sentences includes an incorrect semicolon? In each case where you spot one, can you replace it with a correct punctuation mark?

  • Many of Dickens’s depictions of women are patronising and insipid; nevertheless, he is undoubtedly one of the greatest authors who ever lived.
  • We received few responses to our survey; less than a dozen.
  • Her husband stood at the top of the stairs; he was wearing the shirt that she had given him.
  • Full stops are often used to separate independent clauses; however, if the two clauses are closely linked, a semicolon can be more effective.
  • Her time in the theatre taught her a valuable lesson; confidence is the key to success.
  • While the grown-ups bickered and complained; Vanessa read her fascinating new book.
  • It was the best of times; it was the worst of times.
  • Emma constantly meddles in other peoples’ business; a habit that gets her into trouble.
  • At the laundrette I saw Mary Slater, the shop assistant; Daniel Mechin, the investment banker; and Robert Ferrero, the art teacher.