Cohesion in its broadest sense is “a semantic relation between an element in [a] text and some other element that is crucial to the interpretation of it” (HALLIDAY & HASAN 1994:8). It is basically the glue that holds a text together and makes the difference between an unrelated set of sentences and a set of sentences forming a unified whole.
Cohesion and cohesive ties
The difference of the presence or absence of cohesion for a text is illustrated in the following examples:
- (1) To reach the movie theater you will need to turn right on the next intersection and then go straight for about 5 minutes. You will see it on your right-hand side.
- (2) A cat catches a mouse. The car broke down. I go swimming
While the set of sentences in (1) seems to make sense, i.e. we could easily find the movie theater if we were in the given situation, the set of sentences in (2) does not qualify as unified text, but simply as three completely unrelated sentences. There is no possibility to relate the three sentences in (2) to each other, not even by changing their position.
The difference between (1) and (2) is the presence and absence of cohesion, or better, of so-called cohesive ties. A cohesive tie refers to one “single instance of cohesion” and is a term to indicate “one occurrence of a pair of cohesively related items” (HALLIDAY & HASAN 1994:3). By using the concept of cohesive ties, it is possible to count the amount of instances of cohesion within a given text. Looking at the first examples, it is possible to identify a number of such cohesive ties in (1), while there are no such ties in (2). To illustrate this, one instance of cohesion in the table above can, for example, be identified between “movie theater” in the first sentence and “it” in the second sentence. The “it” refers back to “movie theater” and makes it clear to the hearer that the speaker is talking about the exact same building the hearer wants to reach. Since there are more such cohesive ties in (1), the set of given sentences can be identified as a text, because “[t]he word text is used in linguistics to refer to any passage, spoken or written, of whatever length, that does form a unified whole” (HALLIDAY & HASAN 1994:1). The absence of such cohesive ties in (2) discard the label text for the three given sentences, because of their unrelatedness to each other. “If a passage of English containing more than one sentence is perceived as a text, there will be certain linguistic features present in that passage which can be identified as contributing to its total unity and giving it texture” (HALLIDAY & HASAN 1994: 2). A text needs texture and this texture can only be created by the presence of cohesive ties.
Cohesion occurs where the interpretation of any item in a text or discourse requires the making of a reference to some other item in the same text or discourse (HALLIDAY & HASAN 1994: 11). One item “presupposes the other, in the sense that it cannot be effectively decoded except by recourse to it. When this happens, a relation of cohesion is set up, and the two elements, the presupposing and the presupposed, are thereby at least potentially integrated into a text” (HALLIDAY & HASAN 1994: 4). In other words, sentences are linked by relational elements which combine them to a unified whole that can be called a text. This process, which combines sentences to a meaningful unit, is called cohesion and can be subdivided into the categories: reference, substitution, ellipsis, conjunction and lexical cohesion. “Each of these categories is represented in the text by particular features – repetitions, omissions, occurrences of certain words and constructions – which have in common the property of signaling that the interpretation of [a] passage in question depends on something else” (HALLIDAY & HASAN 1994: 13).
However, cohesion does not only occur in what could be called a cohesive pair, where one only one element refers to another element in a preceding or subsequent sentence and thus forms a cohesive tie which connects the two sentences with each other. So-called cohesive chains frequently occur within a text in which one element of a sentence is cohesively connected to other elements of preceding or subsequent sentences. In some of these cases one element is only indirectly linked to another one, and it is only through cohesive devices that these links become apparent (cf. (3)).
- (3) International pop stars usually lead a very busy life. They need to give concerts, attend photo shootings, or have other important obligations. Very often they have to travel around the globe, jumping from one time zone to another without getting much sleep. There is no secret that many of them have a tendency to take drugs to be able to deal with the pressure. One of the most famous victims of drug abuse during recent years was Michael Jackson who died in 2009 only two months before his 51st birthday.
Example (3) shows such a cohesive chain in which “international pop stars” in the first sentence is connected to all the other sentences via “they” in the second and third sentence and “many of them” in the forth sentence. One has to follow all the cohesive ties in the subsequent sentences in order to establish the relation between the element “pop stars” in the first sentence and “Michael Jackson” in the fifth sentence, i.e. Michael Jackson is an instance of an “international pop star”.
Cohesion vs. coherence
It is also necessary to state that the concept of cohesion is closely connected to the concept of coherence. Although scholars do not completely agree on how to differentiate the two terms “[i]t is generally accepted […] that cohesion refers to the grammatical and lexical elements on the surface of a text which can form connections between parts of the text [while] coherence, on the other hand, resides not in the text, but is rather the outcome of a dialogue between the text and its listener or reader” (TANSKANEN 2006:7). To be able to better understand the concept of cohesion, it is necessary to take a closer look at all the five different kinds of cohesive tie and analyze them in more detail.
Types of cohesive ties
There are five types of cohesive ties which will be analyzed individually below: reference, substitution, ellipsis, conjunction, and lexical cohesion. It is possible to say that cohesion can be “expressed partly through the grammar and partly through the vocabulary” (HALLIDAY & HASAN 1994: 5). Therefore, the five types can be grouped into grammatical and lexical cohesion, i.e. reference, substitution, and ellipsis, fall under the category of grammatical cohesion, while conjunction combines grammatical, as well as, lexical features, and lexical cohesion which is only realized by vocabulary and can be further divided into the categories reiteration and collocation.
The term reference refers to specific items within a text/discourse which cannot be “interpreted semantically in their own right”, but “make reference to something else”, i.e. some other item within the text/discourse, “for their interpretation” (HALLIDAY & HASAN 1994:31). These reference items, which refer to something else, are called directives and indicate “that information is to be retrieved from elsewhere” (HALLIDAY & HASAN 1994: 31). “[T]he information to be retrieved is the referential meaning, the identity of the particular thing or class of things that is being referred to” (HALLIDAY & HASAN 1994: 31) (cf. (4)).
- (4) John goes fishing every other week. He is a very good fisherman.
In (4) the subject of the second sentence “he” refers back to the subject of the first sentence “John”. If the first sentence were not part of the example and a potential reader were only given the sentence “He is a very good fisherman.” the reader would not be able to figure out who “he” is and would therefore not be able to make much sense of the given sentence. The personal pronoun “he” cannot be interpreted semantically in its own right and information about this element of the sentence has to be retrieved from somewhere else, i.e. from the sentence before. “He” makes reference to “John” in the first sentence and thus forms a cohesive tie of reference that connects the two sentences to each other. It is possible to say that “reference is a relation between meanings”, but it is also possible to say that “reference is a relation on the semantic level” (HALLIDAY & HASAN 1994: 89). It is basically a relation, “which holds between meanings rather than between linguistic forms; it is not the replacement of some linguistic element by [another item], but rather a direction for interpreting an element in terms of its environment – and since the environment includes the text (the linguistic environment), reference takes on a cohesive function” (HALLIDAY & HASAN 1994:226f.).
As Figure 1 shows, there are different types of reference, i.e. exophoric and endophoric. Exophoric reference points to the situational context for the interpretation of a specific item. It always refers to something that is not part of a given text and is therefore not cohesive (HALLIDAY & HASAN 1994: 18). Endophoric reference points to other items within a given text or discourse.
- (5) Mike: Hey John, did you just see that?
John: Yes, that was amazing.
Example (5) illustrates an instance of exophoric reference. In the given conversation Mike sees something which he does not explicitly identify as a concrete object. He simply assumes that his conversational partner John saw the same thing as he did and asks him about it. The reader does not get to know what the two friends are talking about and is left in the dark. “That” as reference item in the conversation points outside the text to something that was witnessed by the two interlocutors and, consequently, information about it cannot be retrieved from elsewhere in the text. A potential reader has to use his/her own imagination to create a context, which makes exophoric reference “an essential element in all imaginative writing” (HALLIDAY & HASAN 1994: 18).
Insert Figure 1 here
Endophoric reference points to the textual environment of a given element can be either anaphoric or cataphoric. Anaphoric reference is a form of presupposition and means that a reference item points back to something that has gone before (cf. SCHUBERT 2008:33). Such an instance of anaphoric reference can be found in (4) in which “he” refers back to “John” in the preceding sentence. Cataphoric reference, as oppositional term to anaphoric reference, works the other way around. Here, a usually abstract reference item points forward to a specific element within the subsequent text for its interpretation. In (6) the reader has to look at the whole sentence to make sense of the second word “it” which refers to the specific item “watch” at the end.
(6) There it is, my so much admired watch.
Substitution as another type of cohesive relation, or cohesive tie, is the process in which one item within a text or discourse is replaced by another (cf. HALLIDAY & HASAN 1994:88). While reference was a relation on the semantic level, i.e. between meanings, substitution is a relation on the lexicogrammatical level (level of grammar and vocabulary) “between linguistic items, such as words or phrases” (HALLIDAY & HASAN 1994: 89). A substitute, in its broadest sense, can be seen as “a sort of counter which is used in place of the repetition of a particular item” (HALLIDAY & HASAN 1994:89). Example 7 shows this cohesive relation in which “one” substitutes the word “car”.
- (7) Jack’s car is very old and ugly. He should get a nicer one.
The difference between reference and substitution is that the substituted items are always exchangeable by the items they stand for. With reference the presupposed items can almost never replace the items which refer to them. The table below illustrates this. While in (7) “one” could easily be replaced by “car” without changing the meaning of the sentence (cf. (7´)), “it” in (6) could never be exchanged by “watch” (cf. (6´)). The same is true for (4) in which “he” is not exchangeable by “John” without creating ambiguity. The reader cannot be sure anymore if the “John” in the second sentence is the same person that occurs in the first sentence (cf. (4´)).
- (4´) John goes fishing every other week. John is a very good fisherman.
- (6´) *There watch is, my so much admired watch.
- (7´) Jack’s car is very old and ugly. He should get a nicer car.
Consequently, “the substitute item has the same structural function as that for which it substitutes” (HALLIDAY & HASAN 1994: 89). There are also different types of substitution which are called nominal substitution (replacement of a noun by “one, ones, same”, as illustrated by (7), verbal substitution (replacement of a verb by “do”) and clausal substitution (replacement of a clause by “so, not”) (HALLIDAY & HASAN 1994: 90f.).