Discourse Coherence

4.3 Discourse Coherence based on the Multimodal Metaphors According to the knowledge of discourse coherence, we have known that coherence can be divided into surface level and deep level. This thesis will discuss the discourse coherence from two aspects: cohesion at surface language and structure level and coherence at the meaning level based on multimodal metaphors constructed above.
4.3.1 Cohesion in the Surface Level Cohesion is also a semantic concept, which is realized by the relations in the level of surface language. Although discourse coherence matters not only forms, the research of language cannot carry on without forms. We must study the embodiment of form in order to look for the signs which control the factors

However, there are some differences between the cohesion forms of the two. There are contrast and comparison among the four multimodal metaphors illustrated in the second advertisement, which are good for the formation of cohesion and coherence. “Possibility” and “impossibility”, “life” and “death”, “the common coach” and “the modern school bus” all form a pair of contrast spaces, which belong to the words under the same semantic field. Therefore, the cohesion is formed. What’s more, the extensibility of metaphors takes effect in the formation of cohesion. The continual processes of the little girl’s doubtful expression, the lasting look of the little girl at the sceneries out of the coach window, the coach running to the black tunnel and the frightened looks of children all extend around the tenor of “the common coach” while the continual processes of the modern school bus running out of the black tunnel, the prominent screenshots of steady running on the road, the signs of “school bus” and “stop” and the children getting off the bus happily and cheerfully all extend around the tenor of “the school bus”. Therefore, each metaphor is cohesive and has cohesive relationships with other the metaphors. If we use A for “possibility”, A1 for “impossibility”, B for “life”, B1 for “death”, C for “modern school bus” and C1 for “common coach”, we can observe a metaphor chain as

The theme metaphor is constructed by three sub-metaphors, namely, “Smoking for a man is suicide by gun-shooting”, “Smoking for a woman is suicide by hanging” and “Passive smoking for women is suicide by suffocating”. The three metaphors are constructed in similar ways. The extensibility of the metaphor works in each metaphor. In the first sub-metaphor, the tenor and vehicle both extend to form a balanced parallel progression mode, which embodies the cohesion of the images and metaphor discourse. The written words are correspondences to the images and helper to the construction of metaphor. The situations in the latter two sub-metaphors are the same as that of the first sub-metaphor. The three sub-metaphors are the components of the theme metaphor and they have interconnectivity with each other in the level of cognition. The three sub-metaphors are cohesive with each other by the images and words of smoking and the images which belong to the same semantic field. For example, men and women both belong to the semantic field of “humans”; smoking and passive smoking both belong to the semantic field of “smoking”; suicide by gun-shooting, suicide by hanging and suicide by suffocating all belong to the semantic field of “suicide”. Therefore, each of the three sub-metaphors is cohesive in itself and is cohesive with others. If we use A to stand