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Grammar and punctuation: a user's guide

English is a very rich and complex language and what follows can only draw attention to some of the most common problems and traps. The most effective way of improving your use of language beyond the basics is to read widely and absorb what works.

Note too that some ‘rules’ are matters of taste.


Sentences can be broken up by four symbols: the full stop, the colon, the semicolon, the comma (in descending order of emphasis).

The full stop of course ends a sentence, which can be as little as a verb and its subject: ‘William marched north. The rebels retreated.’ But apart from an occasional use this is too staccato for academic discourse, as is persistent use of simple sentences of subject, verb, object. They work better in bodice-rippers: ‘He threw her over his saddle. She stared into his eyes. They galloped into the sunset.’ In academic writing sentences can be as long as you like (within reason) but the longer they are the more carefully you must steer the reader through them with effective punctuation - and make sure you don’t get lost half way. If in doubt, shorter is better.

The colon [:] usually introduces material illustrating a point made in the opening part of a sentence, which often (but not always) takes the form of a list. See the three colons used above for examples.

The semicolon [;] is generally used to link what could grammatically have been two separate sentences, often to imply a causal connection between them: ‘Alice snatched away the dog’s bone; the dog bit her.’ It is also used (particularly in lists) when using a comma would be unclear – see below for an example.

The comma [,] is the lightest form of punctuation. Its simplest use is dividing items in a list: ‘The three cardinal virtues are faith, hope and charity’ – in such cases note that putting a comma before the ‘and’ (or not) is a matter of taste. Where the items in the list are more complex than this (and especially where the list has been introduced by a colon) it might be clearer to use a semicolon between them instead. For example:

Collingbourne’s verse targeted three of Richard III’s leading allies: the Cat, William Catesby; the Rat, Richard Ratcliff; and Lovell our Dog, Francis viscount Lovell.

Commas are also used to mark off a parenthesis [an aside] in a less obtrusive way than using brackets or dashes (for which see below): ‘The king’s uncle the duke of York, who had not hitherto been politically very active, was now made Regent.’ If you ‘open’ a parenthesis with a comma, don’t forget to close it. Apart from these two roles the use of commas tends to be fairly subjective, but remember that too many can be as confusing as too few. If in doubt, saying the sentence aloud should show you where the breaks come.

Brackets and Dashes. These are ‘stronger’ ways of digressing temporarily from the main thrust of the sentence and mark off the aside more decisively. If, in the example used above, you wanted to identify York you could say ‘The king’s uncle the duke of York (d.1402), who had not…’. Note that a comma must never precede brackets although, as here, it can follow them. Dashes are mid way between brackets and commas in emphasis and are generally regarded as rather informal: ‘Thomas Cromwell – whom Elton idolised – may not have been quite so impressive.’

Apostrophes [’] have two functions. One is possessive: Frederick’s army. Where, as here, the owner is singular the apostrophe precedes the s, where plural it follows it: the rebels’ army. If in doubt try thinking of it the long way round: the flag of the nation = the nation’s flag; the flag of the nations = the nations’ flag. Where a singular noun ends in s, such as St James, the possessive is strictly St James’s – or you could say instead the shrine of St James (or whatever) to avoid the double s.

Apostrophes also signal that something is missing: that’s (= that is), couldn’t (= could not) etc. But this sort of colloquialism should not be used in formal academic discourse. 
These two usages clash in the case of it. It’s is not possessive but = it is (and, as a colloquialism, is out of place in academic writing). The possessive version is its: ‘The lion dragged its prey away.’ Thus: ‘It’s amazing how quickly that cat gobbles its dinner.’

Inverted commas are placed around direct speech and direct quotations. It is now usual to use single commas - ‘Damn’ said the duchess – and only use double commas [“…”] for a quotation within a quotation. If you want to quote at more length, however, indent the quotation without any inverted commas around it, as in the Collingbourne example above.

Inverted commas can also be used to draw attention to a particular word, especially if its meaning is seen as weighted or problematic. A disbeliever in Elton’s view of Tudor government, for instance, might choose to talk of a Tudor ‘revolution’ in government. This is not something to be overdone but it is, in moderation, a useful way of registering a reservation. Note how ‘stronger’ was enclosed in inverted commas above, for instance, to signal that to talk of punctuation as strong and weak is resorting to metaphor.


Tenses. 99% of your essay should be in the past tense: ‘John sealed Magna Carta’. Shifting into the present for dramatic emphasis (‘Brought to bay, John seals Magna Carta’) is almost invariably naff. That said, it is acceptable to say ‘Magna Carta demonstrates the importance of financial issues to John’s opponents’ because that is a present-day judgement. Note that the implication would be slightly different if you said ‘Magna Carta demonstrated the importance of financial issues to John’s opponents’.

There are three past tenses: imperfect, perfect, pluperfect. The perfect is the usual one, describing a completed action: ‘William marched north’. The imperfect describes an ongoing action: ‘While William was marching north there was a rebellion’. The pluperfect describes an action before another one: ‘William had marched north before the rebellion broke out’.

Agreement. Make sure that when the subject of the verb [the person(s) performing the action] is singular / plural, the verb is too. This is not usually a problem with the perfect and pluperfect tenses: he (had) marched / they (had) marched. It is in theory an issue with the imperfect, although no one is likely to muddle ‘he was marching’ with ‘they were marching’. Similarly in the present tense the difference between ‘Professor Postan argues that’ and ‘Marxist historians argue that’ is straightforward. But it can be trickier. ‘None’ is singular [= no one] so ‘none of the soldiers was killed’. Singular nouns for groups of people should also have a singular verb: ‘the council was in agreement’, ‘the army was marching’. But ‘people’ is usually treated as a plural: ‘the people were up in arms’.

Infinitives. The split infinitive (‘to boldly go’) should be avoided (‘to go boldly’ is preferable). But just occasionally a split infinitive is clearer than the alternative and acceptable. Moral: rules are there to be broken (intelligently, not ignorantly).

Shall / will. This can be a nightmare (Fowler, in The King’s English, spends twenty pages trying to unpick them). But the basics are easy. If you are simply using them of something that is going to happen in the future then ‘shall’ is used only in the first person (with I/we) but will for the second and third persons (with you/he/she/it/they). It is therefore incorrect to say ‘my essay shall discuss’ but ‘I shall discuss in my essay’ is correct. What muddies the water is that ‘shall’ can be used with the second and third person to imply an order (You shall go to the ball) and ‘will’ with the first person to imply a strong personal wish (I will go the ball).

May / might. A similar nasty, but in practice the differences between them have all but vanished in modern usage. Two are still worth remembering. Used conditionally the main difference is one of tense: if something happened in the past then something else might have happened (also in the past); if something is happening now then something else may happen (in the future). Note also the difference between ‘If he had observed Magna Carta, John might have avoided civil war’ (a straightforward conditional in the past tense) and ‘John may have agreed Magna Carta but he could not avoid civil war’ (= even though he did x, y still happened).


These are words that bridge two sentences or two clauses within a single sentence. Most can be used in both contexts, the exception is ‘and’, which should not (at least in formal English) begin a new sentence. Conjunctions can operate in various ways.

Most straightforwardly they create a list: and / also / in addition / moreover / similarly. Beware of piling up too many of these; lists are boring. You need to identify the most important items and deal with them in order of priority.

They can create a chronological relationship: when / before / after / during. But avoid falling into a sustained narrative.

They can also register a reservation. This is most simply done by making a statement and then qualifying it, with the modification introduced by words such as but / however / on the other hand: ‘The English won the battle but lost the war’. The structure can be reversed: ‘Although the English won the battle, they lost the war’.

But note that however can = no matter how: ‘However fast he ran, Jane was quicker’. In this case it is not followed by a comma. Compare: ‘However, fast as he ran, Jane was quicker’.


Personal pronouns are I/we/you/he/she/it. These are usually problem free but beware ambiguity. ‘Edward IV pardoned his brother in 1471, he was later drowned in a butt of malmsey.’ It is the brother who was drowned, not Edward. ‘In 1471 Edward pardoned his brother, who was later drowned…’ would nail the ambiguity.


Their official definition is ‘a word or group of words used before a noun or pronoun to relate it to some other constituent of a sentence’ – which doesn’t help very much. In practice they are all those tricksy little words like to / at / in / of.

Most of them – against, between, among, across, beyond etc – are problem free. But note the difference in meaning (now rapidly vanishing under the influence of US English) between the prepositions inside / outside and the nouns inside [of ] / outside [of]:

Joan was standing inside the door (not ‘inside of the door’).
The inside of the door was painted green.

More problematic are cases where a particular word ‘takes’ [= is followed by] a particular preposition or prepositions. ‘King John agreed to Magna Carta’ does not mean the same thing as ‘King John agreed with Magna Carta’. ‘I found a fault in the book’ is not the same as ‘I found fault with the book’. In other cases there is only one option and it has to be right: ‘aggrieved by’, ‘oblivious of’, ‘estranged from’ and hundreds more. The only solution is to buy a good dictionary and USE it.


The same goes for spelling. A spell-check will get you only so far since it cannot pick up words that exist but are wrong (either because mistyped or misused). If in doubt, look it up. English is not a logical language when it comes to spelling - a few common snares follow. Note: many are not the same in US English and might baffle your computer’s spell check.

affect/effect. To affect is to have an (emotional) effect on; to effect is to bring about.
-ant / -ent endings. The difference usually reflects their Latin root, but this does not allow for words that are –ant as nouns but –ent as adjectives e.g. correspondant/ent, dependant/ent, descendant/ent, pendant/ent.
-ecy / -esy endings. When –ecy is a noun, -esy a verb e.g. prophecy / prophesy.
-ence / ense endings. When –ence is a noun and –ense a verb e.g. licence / license.
-ice / ise endings. When –ice is a noun and –ise a verb e.g. advice/advise, device/devise, practice / practise
-ise / -ize endings for verbs. There is a genuine difference of opinion here for many verbs, but some are definitely –ise (e.g. advertise, compromise, despise, devise, surprise) and it could be argued that the simplest thing to do is standardise them all as –ise.
principal / principle. Principal (noun) is a leader, (adjective) primary/leading; principle (noun) a moral imperative. For example: ‘The Principal of Newnham was a woman of strong principles.’

(Rosemary Horrox, January 2010)

The Faculty is currently accepting applications for the Leverhulme Trust Early Career Fellowship match funding by the Isaac Newton Trust. Deadline: 12 pm (noon) on Thursday 2 January 2020.


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