A split infinitive occurs where something comes between the ‘to’ and the verb, e.g. ‘to boldly go’. It used to be considered bad grammar, but is now becoming more acceptable, especially since linguists pointed out that the rule against splitting infinitives was invented by nineteenth-century grammarians who thought that English grammar should work like Latin (where you can’t split an infinitive because it is one word).

Many sentences begin with a participle phrase: a few words with either an active participle (-ing) or a passive participle (-ed). An example is ‘Walking down the street, the woman in red caught Neo’s eye.’ This sentence has to mean that it was the woman in red who was walking, not Neo. If we write this sentence intending the meaning that Neo was walking, then this is known as a ‘dangling participle’. Unlike the rule against split infinitives, which is purely aesthetic and can be ignored when necessary, the rule against dangling participles is important to preserve the meaning of sentences and avoid absurdity.

Subject-verb agreement occurs when the verb has the right singular or plural form for the subject of the sentence; disagreement occurs when you have a singular (or uncountable) subject with a plural verb, or vice versa. A common mistake is to choose the verb according to the noun before it, rather than the subject; e.g., ‘The number of women driving cars have increased.’ Here the verb should be ‘has’, not ‘have’, since the subject of the sentence is not ‘women’ or ‘cars’, but ‘the number of women driving cars’, and ‘number’ is singular.

Adverbials are a large class of words and phrases which modify the meaning of a sentence or give extra information; for example, in the sentence ‘I went to the shops,’ ‘to the shops’ is an adverbial phrase. The most important class of adverbs from the point of view of writing is that known as ‘conjunctive adverbs’ (or ‘adverbial conjunctions’, which is confusing, since adverbials are not real conjunctions). This class includes words like ‘therefore’, ‘however’ and ‘consequently’, and phrases like ‘on the other hand’ and ‘for example’. The important point is that they do not behave like conjunctions. A conjunction is part of the structure of the sentence; normally it will come in the middle of a sentence, and may have a comma before it (see the section of this FAQ on punctuation). A conjunctive adverbial is outside the grammar of the sentence and can go in a number of different places, with a comma before and after; e.g., ‘We see, therefore, that an adverbial can follow a verb, or can, on the other hand, come between an auxiliary verb and a main verb.’ If this sounds confusing, the safest thing is to put the adverbial at the beginning of the sentence, with a comma after it.

These words can be singular or plural, depending on whether you think of them as one group or a collection of individuals. American English generally makes them singular; British English often makes them plural. In other words, it isn’t worth worrying about.

They are plural, but even native English speakers get confused here. ‘Media’ is the plural of ‘medium’, so you should say ‘Television is a powerful medium,’ not ‘Television is a powerful media.’ Similarly, ‘criteria’ is the plural of ‘criterion’; you may hear people say ‘a criteria’, but most dictionaries agree that it is incorrect. ‘Data’ is a special case; it is the plural of ‘datum’, but nowadays it is also used as an uncountable noun, so most people would accept a sentence like ‘Data was processed.’

There is very little difference. Some textbooks say that you should use ‘shall’ with ‘I’ or ‘we’, and ‘will’ in other cases. This is nonsense, as can be seen by Googling ‘they shall’. ‘Shall’ implies intention or even determination; if I say ‘X shall happen’, I mean that X will happen because I will make it happen. You can think of it as a more formal way to say ‘going to’. When in doubt, use ‘will’.

Traditionally, ‘who’ is a subject pronoun and ‘whom’ is an object pronoun, so you should say ‘Who hit him?’ but ‘Whom did he hit?’ However, this distinction is becoming increasingly rare; most British English speakers now use ‘who’ in both cases. If you are not sure which word to use, use ‘who’, since using ‘whom’ where ‘who’ is required looks terrible!

‘That’ is used instead of ‘who'(and other pronouns, like ‘which’ or ‘where’) in defining relative clauses (also known as restrictive relative clauses). For example, you can write either ‘This is the house that Jack built’ or ‘This is the house which Jack built’, although in American English the latter sentence might be considered unusual, and many style guides advise against it. A common mistake is to use ‘that’ in a non-defining (non-restrictive) relative clause. For example, the following sentence is incorrect: ‘Baudrillard, that is a French social theorist, is best known for his idea of ‘hyperreality’.’; in this case, ‘who’ is required.

A colon is a bit like an equals sign: it means what is on the left of the colon is the same as what is on the right (as in this sentence). For example, ‘Linux has five main advantages over Windows: stability, privacy, power, safety from viruses, and the fact that it is free.’

Semi-colons have two main functions. The first is to join two sentences when you don’t want to use a conjunction (‘Alcohol is often thought to make people more lively; in fact, it is a depressant.’). The second is to separate long items in a list instead of a comma, for example, ‘The different varieties of Fascism share a number of characteristics: extreme nationalism; moral conservatism and nostalgia; control of all cultural activities; militarism; hostility towards minority groups, and anti-intellectualism.’

American writers generally put a comma there (‘The UK consists of England, Scotland, Wales, and Northern Ireland.’) unless there are only two items in the list. British writers do not normally bother with one, unless it is necessary to make things clear (‘I had soup, fish and chips, and ice cream.’).

Dates do not need an apostrophe, since they are not possessive (like ‘Mary’s’), and no letters have been missed out (like ‘doesn’t’). So you should write ‘the 1960s’, not ‘the 1960’s’. You should put an apostrophe before the date if you shorten it (‘the ’60s’).

A hyphen is a short line used to join two words (‘blue-black’), to separate parts of a word (e.g., ‘pre-ordered’) or to indicate that the rest of the word is on the next line. Dashes come in two forms. An en dash is slightly longer than a hyphen, and is used for ranges (‘1979‒1983’). An em dash is longer still, and is mainly used instead of a semi-colon or parentheses — it’s a kind of all-purpose punctuation mark. Most word processors have a feature which changes a double hyphen to an en dash and a triple hyphen to an em dash. Note: on some older browsers, the dashes here will be replaced by strange codes—if you see these, it’s time to upgrade your browser! Again, depending on your browser, the hyphens and dashes here may all come out the same length.

There is no difference. ‘Period’ is American English, and ‘full stop’ is British English.

There is no agreement on this question. In British English, it is normal to put a full stop or comma before the quotation marks if the quoted matter is a complete utterance; e.g., ‘Sally said ‘I’m bored.” (note how quotations inside quotations take single quotation marks!). However, if only a word, a short phrase or the title of an article etc. is inside the quotation marks, then the punctuation goes afterwards; e.g., ‘Byron’s greatest poem is ‘Don Juan’.’ In American English, the rule is to put the punctuation before the closing quotation marks, whether or not it makes sense. In the case of question marks and exclamation marks, it depends on whether they are part of the quoted sentence, so we would write ‘Sally shouted ‘I’m bored!” but ‘Did Sally say ‘I’m bored’?’.

There is no agreement on this question. Most typing courses recommend typing two spaces at the end of a sentence or after a colon; most style guides say you should only ever have one space after punctuation. In professional publishing, the amount of space is calculated according to some quite complex mathematics, so that the space after punctuation within a sentence is slightly greater than the normal space between two words, and the space after a sentence is a little longer than that. Unfortunately, most word processors either can’t do this, or do it badly (LyX is an exception). The important thing is that you remember to leave at least one space!

Older textbooks and style guides advise against the use of contractions; however, a quick look at papers published in academic journals will show that they are now quite common. If you are not sure, it is best to write them out in full: ‘cannot’, ‘I will’ and so on.

Older textbooks and style guides sometimes advise against using the first person, but in fact it is quite common in academic writing, except in science journals (and even some scientists have started using the first person). The Fifth edition of the APA style guide actually recommends using the first person as an alternative to the passive voice. The important question is not whether you use the first person, but where and why. It is most common in introductions of papers (e.g., to introduce a thesis statement) and to introduce opinions where the writer wants to emphasise that it is only his or her opinion. It is used much less for conclusions, as concluding with a phrase like ‘I think’ or ‘In my opinion’ can have the effect of weakening the argument by making it look subjective.

It depends on the kind of conjunction and your reason for using it. Some co-ordinate conjunctions, like ‘and’, ‘but’ or ‘so’, may be used to start a new sentence if, and only if, you want to emphasise the conjunction; it has the same effect as a pause in speech. In formal writing, subordinate conjunctions (like ‘because’ or ‘since’) should only be used at the start of a sentence if you reverse the order of the clauses; e.g., ‘Because he had not slept, he found it hard to concentrate.’

Some textbooks say that the passive voice is better in academic writing; others tell you to avoid it whenever possible. In fact, there is no strict rule. The passive voice is more common in scientific writing (‘Copper Sulphate was added to the solution’) but even NASA now recommends using the active voice in most cases. The passive is best used when the agent (the person or thing performing the action) is unimportant or unknown, or when you want to emphasise the patient (the person or thing that has something done to him/her/it). In academic writing it is common to introduce ideas with passive-voice phrases like ‘it is thought that’or ‘it can be concluded that’; however, you should not overdo this; use these phrases from time to time, but not in every second sentence! You should definitely avoid meaningless ‘by’ phrases, as in ‘The Internet is used by many people’ (obviously it is not used by many dogs).

Whichever pronoun you use, someone will object to it violently. If you use ‘he’, you can be accused of ignoring women; if you say ‘he or she’, you will be criticised for using too many words; ‘he/she’ will be criticised as ugly; and ‘they’ will be damned as ungrammatical (even though it isn’t). You can’t win, so try to find a way to make it plural or avoid using a pronoun at all!