The fi rst two examples discussed below illustrate different ways in which the linguistic model is used to develop a narrative model, and ( ).

The pronoun this is typically used as a subject with the verb be to refer back to an example given in a previous sentence (see Example 4.15 above). Right co-occurrents include the preposition of and the pronoun this. In 40 per cent of its occurrences, the noun example is directly followed by the preposition of which introduces the idea, class or event exemplifi ed, which in turn is often determined by a demonstrative (Example 4.31 above) or pronominalized to refer back to a previous sentence.

These fi ndings support Gledhill’s (2000) view that there may be a very specifi c phraseology and set of lexico-grammatical patterns for function words in academic discourse. Function words seem to display co-occurrence preferences just as content words do (also see Renouf and Sinclair’s (1991) notion of a ‘collocational framework’). These fi ndings also provide strong evidence against the use of stopword lists when extracting co-occurrences from corpora as there is a serious danger of missing a whole set of phraseo- logical patterns (Clear, 1993).

The verbs illustrate and exemplify can also be used as exemplifi ers. The verb illustrate is used with the meaning of ‘to be an example which shows that something is true or that a fact exists’ (Example 4.35) or ‘to make the meaning of something clearer by giving examples’ (Example 4.36) (LDOCE4). The verb exemplify is used with the meanings of ‘to be a very typical example of something’ and ‘to give an example of’.

4.35. The narratives of the Passio Praeiecti and of the Vita Boniti both have their peculiarities, and it is possible that the appointment of Praeiectus and the retirement of Bonitus were less creditable than their hagiographers claim. Nevertheless they do illustrate the complexities of local ecclesiastical politics. 4.36. My aim will be to illustrate different ways of approaching literature through its

linguistic form, ways involving the direct application of linguistic theory and linguistic methods of analysis in order to illuminate the specifi cally literary character of texts.

Both verbs are more frequent in academic writing than in any other genre. Figure 4.5 compares the relative frequencies of the two verbs in academic writing with three main genres represented in the British National Corpus. The verb illustrate is not uncommon in news but a quick look at its concor- dances shows that a signifi cant proportion of its occurrences are used not to introduce an example, but with the meaning of ‘to put pictures in a book, article, etc’ (Example 4.37). Exemplify is very rarely used in other genres.

4.37. Also in the pipeline is an Australian children ‘s TV series based on Gumnut Factory Folk Tales (written, illustrated and published by Chris Trump). (BNC-NEWS)

Figure 4.5 also shows that the verb illustrate is more frequent than exemplify in professional academic writing. The frequencies of the two verb lemmas, their word forms and tenses in the BNC-AC-HUM4 were computed in the way described by Granger (2006). Table 4.6 shows that there is no

Rhetorical functions in expert academic writing 103

major difference in proportion between the verb forms illustrate, illustrated and illustrates. When used in active structures, the verb is often preceded by a non-human subject such as example, fi gure, table, case or approach (Example 4.38). Almost all occurrences of the past participle appear in the passive construction BE illustrated by/in (Example 4.39).

140

120

100

80

60

frequency per million word

40

20

Academic News Fiction Speech

0

illustrate exemplify

Figure 4.5 The distribution of the verbs ‘illustrate’ and ‘exemplify’ across

genres

Table 4.6 The use of the lemma ‘illustrate’ in

the BNC-AC-HUM

The lemma illustrate BNC-AC-HUM illustrate simple present infi nitive 97 36 61 37.45% 13.89% 23.55% illustrated simple past present/past perfect past participle 84 7 0 77 32.43% 2.7% 0% 29.73% illustrates 63 24.32% illustrating continuous tense -ing clause 15 2 13 5.79% 0.77% 5% Total 259 100% Nr of words 3,321,867

Relative freq. per 100,000 words

4.38. This example clearly illustrates the theory dependence and hence fallibility of observation statements.

4.39. The contrast between the conditions on the coast and in the interior is illus- trated by the climatic statistics for two stations less than 30 km (18.5 miles) apart.

The sentence-initial adverbial clause To illustrate this/the point/X, . . . (Example 4.40) represents 2.7 per cent of the occurrences of the lemma illustrate in the BNC-AC-HUM.

4.40. How many observations make up a large number? (. . . ) Whatever the answer to such a question, examples can be produced that cast doubt on the invariable necessity for a large number of observations. To illustrate this, I refer to the strong public reaction against nuclear warfare that followed the dropping of the fi rst atomic bomb on Hiroshima towards the end of the Second World War. In the BNC-AC-HUM, illustrate signifi cantly co-occurs with the noun exam- ple [LogL = 112] in a 3L-1L window, and with the nouns point [LogL = 168.78], example [LogL = 49.65] and fi g. [LogL = 45.08] in a 1R-3R window. The noun point is used as an object of illustrate which refers back to an idea put forward in a previous sentence:

4.41. For most of this century it is those disorders gathered together under the head- ing of ‘schizophrenia’ that have been used as the paradigm for trying to describe and understand psychosis. Yet even in this form, or forms – for many would prefer to talk of ‘the schizophrenias’ – there is still no universally accepted set of criteria for diagnosis. To illustrate the point, one of the present authors was recently asked to review a paper submitted to a prominent psychiatric journal, proposing a new set of rules for diagnosing schizophrenia. In the course of their analysis the authors determined the extent to which their proposed criteria agreed with those contained in other existing diagnostic schemes – some ten or twelve of them. Correlations varied over a very wide range.

The noun fi gure (and the abbreviation fi g.) is used either as the subject of the verb illustrate or in the passive structure illustrated in Figure x. This co-occurrence is even more marked in academic genres such as social sciences, natural sciences and medicine which rely extensively on fi gures, tables and diagrams (see Examples 4.42 and 4.43).

4.42. Figure 1 illustrates the spread of results for the alcoholics and the controls.