Demonstrative pronouns
Demonstrative pronouns (this, that, these, those) play an important role in text cohesion because they have indexal (pointing) and referential functions (Halliday & Hasan, 1976). However, demonstratives can be ambiguous and vague when it is not immediately clear what specific noun or phrase they refer to. Research into academic text has found that demonstratives are comparatively common precisely due to their lack of specificity and their ability to project objectivity (Biber, 1988; Myers, 1989). However, this occurs far more frequently than these, that, or those, whereas the combined frequency rate of all demonstrative pronouns stands at 0.45% per million words of academic prose (Biber et al., 1999). In general terms, demonstratives are one of the simplest cohesive devices in English. In their attempts to make their text cohesive, L2 writers often misconstrue the limited cohesive capacity of demonstratives or rely on them to excess (Hinkel, 2001a, 2002a). Consider the following example:
Since cows are housed in areas that cannot he kept dean, there is an increased disease incident and other health problems, which result in high input costs. This is the reason why other farming systems are being considered for lowering this cost of milk production.
In the example, the first occurrence of this actually refers to several "reasons" that "other farming methods are being considered" (i.e., a lack of cleanliness in cow housing, increased incidence of disease, and high input costs). However, in English a singular demonstrative pronoun has a limited referential capacity and cannot refer to a number of referential points at one time. The second this refers to a plural noun costs that is not located in the immediate proximity to the pronoun. In both cases, the use of demonstratives makes the text appear confusing and somewhat obscure. In general terms, the use of demonstratives requires adherence to largely rigid noun-pronoun agreement in number (i.e., singular pronouns this and that cannot refer to plural nouns). In most cases, this and these can "point" to nouns in their close proximity (or a close proximity to the speaker, as in This is a great computer, when one is looking or pointing to a computer). However, that and those are markers of a more distant reference. However, neither type of demonstratives can refer to a sizable portion of text, as can often be encountered in students' texts (Hinkel, 200la).