60. Purpose Sentences with “For”

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Running FOR Victory

The word “for” acts differently in different kinds of purpose sentence, and sometimes causes errors as a result

THE PROBLEM POTENTIAL OF PURPOSE-SHOWING “FOR”

Purpose sentences often contain the preposition for. However, there are some rather confusing rules concerning this word in purpose sentences, and as a result some common errors made with it. A particularly noticeable error is combining for with an -ing verb, like this: 

(a) *Afterwards the dancers go off for enjoying themselves. 

Although an -ing verb can sometimes be used after for to express a purpose, it cannot in this example sentence (see 165. Confusions of Similar Structures 2, #3). Possible corrections include to enjoy, in order to enjoy or so that they can enjoy. In this post I wish to examine exactly when you can and cannot use for in a purpose sentence.

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THE BASIC FEATURES OF PURPOSE SENTENCES

Purposes are future events or situations that living creatures seek to achieve by doing something. Consider these examples: 

(a) Doctors STUDY anatomy so that they MAY UNDERSTAND sickness.

(b) Colleges TEACH anatomy so that doctors WILL UNDERSTAND sickness. 

The underlined words are purposes. The living creatures that want to achieve them are doctors in (a) and colleges in (b). The things being done to achieve the purposes – what we might call the “means” of achieving them (see 73. Prepositions for Saying How) – are shown within the words that are not underlined. 

In these examples, the purpose and a means of achieving it are expressed with separate verbs, though elsewhere one or both may be a noun (see 81. Tricky Word Contrasts 2, #3 and 119. BE before a “to” Verb, #1). With two verbs, their subjects may represent the same idea – “doctors” in (a) – mention of the second being with a pronoun (they); or they may represent two different ideas: colleges and doctors in (b).

The words so that before the purpose in (b) are a conjunction: they allow the two verbs to be in the same sentence (see 230. Multi-Word Conjunctions). An alternative purpose conjunction is the slightly more formal in order that. With these conjunctions, the purpose verb must usually contain can, will or may or their “past” equivalents could, would or might (see 32. Expressing Consequences).

Three other synonyms of so that are to, in order to and so as to. However, because they have to instead of that, their following verb cannot contain may etc. (see 231. Confusions of Similar Structures 3, #3). They also need their subject to be expressed differently. Compare:

BOTH SUBJECTS THE SAME WITH “to”

(c) Doctors study anatomy (in order/so as) to understand sickness. 

Here, the repeated subject is left out – using they is not possible.

BOTH SUBJECTS DIFFERENT WITH “to”

(d) Medical colleges teach anatomy (in order) for doctors to understand sickness. 

In this case, the different second subject (doctors) has to be mentioned. It needs for because the verb has to. Note that so as to cannot replace to.

The use of for in (d) illustrates what is probably its most important one in purpose sentences. It can be summed up like this: 

1. For and its noun go directly before to.

2. The noun expresses the subject of the to verb, not the purpose itself.

3. The to verb’s subject is not the same as the other verb’s subject.

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OTHER USES OF “for” IN PURPOSE SENTENCES

In other uses, for is more associated with the purpose itself than its subject. There are two main kinds of use: with a noun and no verb after for, and with a verb and no noun (a noun and verb together can only be the use described above).

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1. “For” + NOUN meaning “in order to have”

English quite often uses for + NOUN to mean either “in order to obtain”, “in order to receive” or “in order to have”. In these cases, the noun after for shows what the purpose holder wants to possess or achieve. Here are some examples: 

(e) Students have to work hard for good grades.

(f) The patient needs to return to the clinic for a reassessment.

(g) For a full explanation, please turn to page 6.

(h) It is healthy to go for regular walks. 

Although no verb is present among the purpose words in such sentences, the “have” meaning of for ensures a verb idea is still present.

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2. “For -ing” meaning “in order to do” (after certain verbs only)

Expressing “in order to do” with for -ing only seems possible when the main verb in the sentence is one of a small group, a common example being USE. Here is a typical purpose sentence containing USE:

(i) An ammeter is used for measuring electric current.

Instead of an -ing verb after for, one could also use an “action” noun (for the measurement of… – see 131. Uses of “Action” Nouns). The passive form (is used) seems especially common in such sentences, but the active is certainly possible too (e.g. We use an ammeter…).

Other verbs which allow for -ing meaning “in order to do” are HAVE, KEEP, NEED and ALLOW, as well as their synonyms (e.g. POSSESS, MAINTAIN, STORE, REQUIRE and PERMIT). Adjectives related to them can also be used in combination with BE, common examples being useful, of use, valuable, helpful, good, suitable, necessary, optional, requisite, important, vital, essential, crucial, compulsory and mandatory.

It is this restriction on the verbs usable with for -ing that makes sentence (a) above incorrect: the verb GO there is not one of the allowed kind. GO seems to be a verb that is particularly often used in this erroneous way, perhaps because it can separately combine with either for or -ing (see 176. Ways of Using GO). DO SOMETHING is another verb that is often incorrectly combined with for -ing.

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A NON-PURPOSE USE OF “for -ing”

If for -ing is not used with the above verbs, it will either sound incorrect or express a function rather than a purpose. Functions name what something does, rather than what people hope it will do (see 119. BE Before a “to” Verb, #2). Consider this:

(j) Chlorophyll in plants is for utilizing solar energy.

Chlorophyll here is not consciously trying to perform its function.

The function and purpose uses of for -ing are recognisable from their grammar as well as their meaning. The function usage tends to act like an adjective in sentences, the purpose one an adverb. Adjective-like uses describe a preceding noun while adverb-like ones say something about a verb (see 84. Seven Things to Know about Prepositions, #2).

In sentence (i) above, for example, for measuring… is describing the verb is used and is hence adverb-like and purpose-naming. In (j), however, for utilizing… is describing the noun chlorophyll and is hence adjective-like and function-naming. This particular adjective-like use is separated from its noun by the verb BE. In other cases, however, the noun and for -ing might be together:

(k) The form has a SPACE for giving extra information.

This names the function of the mentioned space.

In the following example, things are slightly more complicated:

(l) The company provides BUSES for transporting its employees.

Does this name the purpose of the company or the function of buses? Grammar is of less help here because the preposition phrase could be either adjective-like or adverb-like: it could be linking with either the verb provides or the noun buses (see 124. Structures with a Double Meaning 1, #2). However, there is still a clue that the use is adjective-like and function-describing: provides is not one of the above-listed verbs that allow a purpose to be described with for -ing. In order to express a purpose, for would need to be used in the first way described above: for + noun + to… (…for its employees to be transported in).

Note that some noun functions can also be expressed with a to verb. This is not possible in (k) (space to give there would be an abbreviation of space for people to give – a purpose statement), but one could write buses to transport in (l) (see 239. Noun Phrases Made with a “to” Verb). The reason for the difference is that space in (k) is not the subject of the verb after it (GIVE), but buses in (l) could be. A problem with saying to transport after buses in (l), however, is that two alternative understandings would be possible: it could express the purpose of the company as well as the function of buses.

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PRACTICE EXERCISE: “for” IN PURPOSE SENTENCES

Readers wishing to test their understanding and memory of the points above may like to try the following small exercise. The sentences must be judged as grammatical or ungrammatical purpose statements, and corrected where necessary. Suggested answers are given afterwards.

1. Drivers look at a speedometer for knowing how fast they are travelling.

2. Headlamps should be switched on for the vehicle to be visible in fog.

3. It is sometimes wise to sound the horn for safety before a bend.

4. For preventing evaporation, the fuelling pipe needs a cap.

5. Cars have indicators for the driver giving warnings.

6. Switch on the air conditioning for travelling in comfort.

7. For journeys without stress, cruise control is available.

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Suggested Answers

1. Rewrite for knowing as (in order) to know (for + -ing is not possible with the main verb look at).

2. No change (for+ SUBJECT + to+ PURPOSE VERB).

3. No change (for + NOUN = “in order to obtain”).

4. No change (for + -ing with acceptable verb needs).

5. Either delete the driver so as to leave for + -ing after HAVE, or rewrite giving as to give to make for + NOUN + to.

6. Rewrite for travelling as (in order) to travel (for + -ing is not possible with the main verb switch on).

7. No change (for + NOUN = “in order to obtain”).

59. Paragraph Length

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English Paragraphs do not have “new lines” and should on average be 5-6 normal sentences in length

THE SUBJECTIVITY OF SOME LANGUAGE DECISIONS

Some language decisions in writing have no clear rules but instead require subjective judgement. Examples from elsewhere within this blog are the choice that can be made in English between a full stop and a semi-colon to show how closely two statements are felt to be linked together (see 17. Colons versus Semi-Colons), the decision whether or not to give a list as bullet points (74. Sentence Lists 3: Bullet Points), and the length of sentences in a text (265. The Importance of Grammar in Writing).

Dividing what you have to say into paragraphs is also quite subjective. It involves various types of choice, but the one I want to concentrate on here is the length that paragraphs should have. Although not everyone would agree that paragraph length is a subjective choice, I would argue that it is on the evidence of the way English paragraphing differs from that of some other languages. My primary aims in this post are to clarify this difference, and to argue that English paragraphs should in general average about five or six sentences in length.

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HOW ENGLISH PARAGRAPHING DIFFERS FROM THAT OF SOME OTHER LANGUAGES

Writing customs are not the same in every language, and there are some noticeable differences between the customs of English-speaking countries (and other countries with historical links to Britain) and those in most other European countries (and countries with historical links to them). Of these, the English preference for etc instead of three dots (…) features in the Guinlist post 1. Simple Example-Giving, and the English use of indirect questions instead of direct ones for introducing a topic is highlighted in 57. Indirect Questions in Formal Writing. Vocabulary with very specific English meaning is illustrated in 137. Words that Reflect English Culture.

In paragraph writing, a major difference is that English-speaking writers use text divisions of a single kind, while most other European writers use two kinds of division: “new line” and “new paragraph”, which respectively show weaker and stronger divisions. A new line is made by beginning a sentence at the start of the next line even when there is enough space to begin it on the old one. Here is an example:

As this example also shows, a “new paragraph” begins on a new line too, but is separated from the old one by a space. It therefore looks like an English paragraph made in the “block” style. But is it really the same?

Many years ago, when I was tutoring French university students in London, the advice I gave about writing in the English style was simply to avoid new lines. However, the consequences soon showed that there was more to the difference between English and “Continental” paragraphing than this. Most of the students who tried to follow my advice still produced paragraphs that were not quite right: too long in the majority of cases, and too short in some.

It seemed to me that the long paragraphs resulted from the new-line divisions being removed, leaving only the Continental paragraph divisions, while the short paragraphs resulted from English-style paragraphs being introduced wherever a new line would have occurred. If this was the correct cause of the unsuitable paragraph lengths, then it meant that neither Continental paragraphs nor new lines correspond exactly to English paragraphs, the former making stronger divisions, the latter weaker ones. The implication for writing in English is that some places where a Continental writer might make a new-line division should be made to start an English paragraph, but not all. The problem then is to decide which.

The determinants of paragraph divisions in a text are, of course, natural breaks in the information being communicated. Some might argue that these are fixed and objective, so that they take the decision about where to make paragraph divisions out of the writer’s hands altogether, and replace it with a need merely to uncover the Truth of their location. However, the fact that English and Continental paragraphs do not always begin and end in the same places suggests that these natural breaks are not so naturally fixed and in fact would be different for different writers. Some differences will be in the strength of breaks, and some will even be in what are and are not natural breaks.

When there is so much subjectivity about natural information breaks, the actual length of paragraphs must take on some importance for deciding where to end them. I believe that both English and Continental writers do follow unconscious length conventions, which are determined by the wider society they live in. This does not mean that length is the only or main criterion for ending a paragraph; paragraphs must always end at a natural information break. But, if a paragraph is getting longer than the customary length, and a natural information break (a weak one if necessary) can be found at a point closer to where the customary length would be achieved, then it would be normal to end the paragraph there and continue anew.

I would suggest that the average length of English paragraphs is about five or six normal-length sentences (following the sentence definition given in the post 30. When to Write a Full Stop). I am being deliberately cautious here in using words like “average”, “about” and “or”. This is partly because individual paragraphs are very frequently longer or shorter than this (it is only the average that is important), and partly because the basis of the suggestion is intuition rather than objective study. The intuition became explicit for me during countless hours spent reading essays by international university students. Like most tutors, I was moved on occasion to question paragraph lengths, and was forced as a result to think about why I felt the paragraph length to be wrong and what length I should recommend.

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AN EXAMPLE OF CHANGEABLE PARAGRAPH DIVISIONS

To finish, I wish to present some examples of how information can be broken up in different ways so as to produce different paragraph divisions. How many paragraphs should the information in this diagram have? .

Since the diagram shows four different kinds of environmental pollutants, four paragraphs – one for each – seems at first sight appropriate (the list item on the left described last because of its length – see 222. Information Orders in Texts, #3). The problem, however, is that the two kinds on the right, nuclear waste and rubbish, do not look to involve very much information, so that separate paragraphs for each would probably be very short.

Could the two short topics be combined into a single paragraph, giving the text as a whole three paragraphs instead of four? There is no reason why not – many writers are happy to combine shorter parts of lists into the same paragraph. There is not even any need to generalise the two headings with a single “list name” (see 55. Sentence Lists 2: Main-Message); the third paragraph could simply be introduced with a list sentence like The n^th and n^th types of environmental pollutant are… .

In the same way, a single subdivision that looked very long would not have to be presented in a single paragraph. The longest subdivision in the above diagram, for example, might take up two paragraphs: one about gases and one about particles. Such an information division is certainly as natural as any other in the text.

Thus, the overall suggestion of this post is that physical length of paragraphs should be consciously considered to check that it averages 5-6 sentences. If the average is longer, there is nearly always a natural break in the information where some paragraphs can be split into two.