Characteristics of Conceptual Metaphor: A Case of Metaphorical Expressions Based on Human Senses in Vietnamese

Conceptual Metaphor (CM) is the main factor in the thinking process of people as well as in the way people perceive the around world and at the same time. Although they are using conceptual metaphors, they do not find it is a metaphor. In the view of Cognitive Linguistics (CL) a quite new approach in linguistics considering language as part of general cognition and thinking. Regarding language as an essential part of cognition, the field of metaphors has been focused on in the research of linguistics in the world. This may be explained that researchers have found the general characteristics of metaphors in languages. Vietnamese is not an exception, especially in expressing CM based on human senses (HSs). In other words, in Vietnamese, people use conceptual metaphors in a way that think or conceptualize the “target” domain through the “source” domain by experiencing their body parts and the nature systematically. This article refers to the characteristics of metaphors in the view of CL in detail along with special evidences in Vietnamese metaphorical expressions based on HSs. The related words and phrases were saved in order to serve examining their meanings if they were concrete or abstract in the view of CL in the online dictionaries so that the meanings of them were explained the most completely along with the descriptive, analytic and synthetic methods which are for describing the data collected to set up a foundation for analysis in clarifying the CM’s characteristics. The study brought a both general and particular view for learning a language with a hope to be applied in the research’s content for teaching, learning and translating for learners or researchers of Vietnamese more effectively.


Introduction
Beginning to form in the 1970s, Cognitive Linguisitics (CL) -a part of Cognitive Science, has become a research interest of many linguists such as: Lakoff, Johnson (1980/2003, Evans andGreen (2006/2007), Tendahl (2009), Kövecses (2010),.. In about 10 years after appearing, CL has exploded many researches with the introduction of the International Recognized Linguistic Society and Recognized Linguistics Magazine. According to Langacker, this event noted that CL was a self-conscious intellectual movement with a strong foundation [7]. CL is a new school of modern linguistics that conducts language research on the basis of human experience and perceptions of the objective world as well as the way people perceive and conscious recite the things and facts of that objective world [1]. CL focuses on studying "human language in the most natural form with directly observable linguistic facts and even direct observations such as intellect, knowledge, ideas etc." [13]. In other words, language is a form of perceived activity. As a cognitive tool, language is a symbolic system that plays an important role in expression and in information transformation. In this view, language is seen as an independent object to people. Indeed, its function of historical expression is not separate from the communication function [12], especially in the case of metaphor.
The metaphor from CL's point of view, called the cognitive metaphor or conceptual metaphor (CM), has been studied very extensively from many different dimensions of the world: Lakoff, Johnson (1980/2003 In fact, there is a variety of metaphoric approaches in Vietnamese but from the point of view of CL, metaphors have their own characteristics that need to be clarified more through the evidences in Vietnamese metaphorical expressions based on human senses so that learners of Vietnamese can be approached in understanding, producing, and creating meanings of expressions.

Tenets of Conceptual Metaphor
Definition According to cognitive linguists, metaphor does not exist only in language but first of all in our thinking, existing in our conceptual system, existing in our words and actions. In other words, in everyday life, people often think and express in words which are metaphorized. They often refer to wellknown, tangible, and specific notions to identify, to think about intangible, abstract, and difficult-to-define concepts. In CL's view, it is called conceptual metaphor or cognitive metaphor. Also, according to Lakoff and Johnson, in a society with a certain culture, the metaphor concept will become a major system that plays a major and decisive role in the objective awareness world of human [6]. A metaphorical expression is primarily an extension of knowledge, providing an understanding of an object through an understanding of another known object. In this way, people create new insights [14].

Classification of Conceptual Metaphor
According to cognitive linguists as Lakoff and Johnson, metaphors are classified into the following main categories: structural metaphor, ontological metaphor, conduit metaphor, orientational metaphor and container metaphor [6].
A metaphor which can be considered an important feature of understood (evaluated) through the structure of another word (or expression) is called a structural metaphor. The transgression of abstract entities by their boundary lines in space is called the ontological metaphor. The conduit metaphor is the communication process such as the movement of the meaning of "filling" the language expressions (containers) by channel connecting the speaker to the listener. The orientational metaphor is to organize a whole system of ideas for another system, most of which involve spatial orientation: top-down, up-down, in-out, shallow-deep, front-back, etc. This is the kind of metaphor that gives the idea of a spatial orientation. What symbolize ideas that are understood as "filling containers" -specific language units, are called container metaphors [11].

Research Method
Through our observation in daily life of people, we conducted to collect expressions based on HSs in Vietnamese which they usually use to express their thoughts. The related words and phrases based on HSs were saved in order to serve examining their meanings if they were concrete or abstract in the view of CL. Examining the meanings is also done by the online dictionaries. Therefore, the meanings of them were explained the most completely. However, for the words which had many meanings, we chose the best one for the situation in the context.
Because the evidences for studying are in Vietnamese, we included an English translation and kept their metaphorical meanings in Vietnamese along with a gloss inside bounded by single brackets with the explanation of meanings in details.
The methods used to conduct this study are descriptive, analytic and synthetic methods which are for describing the data collected to set up a foundation for analysis in clarifying the characteristics of CM.

Conceptual Metaphors Based on Human Senses in Vietnamese Considered in Their Characteristics
In the concepts presented about CM above, along with the views of the cognitive linguists as Lakoff, Johnson, Richards, Lee, Evans, Green or Kövecses, we conducted the study on characteristics of CM in details through the evidences of Vietnamese metaphorical expressions based on some HSs to transfer the thought of people in daily life.
a) The first characteristic is that metaphor is not a linguistic phenomenon, in principle, it belongs to the scope of thinking, is the fundamental characteristic of everyday language.
In the past, metaphors were considered a special form of discourse, only a characteristic in literature. Lakoff and Johnson identified that human thinking comes from metaphor [6]. Johnson argued that "many regions of experience, understanding, reasoning and practice are structured metaphorically." [2] Lee provided some evidence for this observation: in the UK, the official Ministry of Defense publications and in the House of Representatives speeches, a series of metaphors were obtained. For example, "Nuclear weapons are economic, industrial and technological processes". In this situation, interpret particle weapons as economic, industrial and technological processes; refer to them as parts of the nation's machine that produces wealth [9].
In daily life, people use objects and phenomena or objects that are close and symbolic to metaphor about what they need to express. For example, in the case of structural metaphor, we can see many symbols used by people like life -journey as in the conceptual metaphor LIFE IS A JOURNEY: the road represents life, on the way there are difficulties such as trees, thorns or bends we must go through as we have to go through those difficulties in our life. In Vietnamese, we can see the expressions such as (1) "Bọn trẻ đã bắt đầu đi vào con đường chông gai của cuộc sống" (The children have begun to enter the thorny path of life).
Besides, considered to be an example of ontological metaphor, the human body is abstracted by the boundary (heart, stomach) where the idea comes to the emotion of the person (faithful). The expression in Vietnamese (2) "Tuấn vẫn một lòng một dạ với cô ấy" (Tuan still has a heart for her).
is an example. Indeed, Lakoff and Johnson have also identified that people often use the relationship between emotion and body, to create a conceptual structure deeply behind those expressions, so there may be a conceptual metaphor for "BODY IS A CONTAINER FOR THE EMOTIONS" [5]. Besides, changes in weather and climate are also symbols of changes in people's inner emotions. For example, in (3) "Gió hiu hiu lòng tôi bỗng nghe lạnh" (The wind puffs lightly my heart feels cold).
The degree of wind, a natural phenomenon, and changes to a "hiu hiu" state that represents a feeling of chill, sadness makes people touch the feeling of loneliness and sadness. That feeling is received and transmitted to the listener through HSs.
The metaphorical expression "Gió hiu hiu lòng tôi bỗng nghe lạnh" in Vietnamese is the basis sample for the conceptual metaphor "EMOTION IS CLIMATE". The perception of the activity "hearing" is likened to an information channel, through which the listener takes out the thoughts/ objects from the spoken words. The weather or climate seems to be connected with people everywhere in the world, when observing the weather forecast is a very familiar thing in everyday life right from the human mind. Its changes become a symbol of the change in emotions they experience and convey through their language expressions. Therefore, the notion of words when people use is very diverse and interesting. For the orientation, we can find quite many expressions using words based on HSs to show the ideas. Following is a sample (4) "Hắn nhìn ông chủ bằng đôi mắt sâu hun hút của sự thù hằn" (He looked at the boss with the very deep eyes of enmity).
The words 'sâu hun hút' refers to the direction of the object, means 'reaching the bottom'. In this example, the expression "... look... with the very deep eyes of enmity" transfers the idea to extremely big enmity that reaches to the absolute level. In addition, the human body is also considered a container. The visual part (eye) as if it were a "container" in (5) "Tôi thấy trong mắt anh cả một trời buồn tủi" (I saw a sadness in his eyes).
The eye is likened to a box filled with 'sadness'. Indeed, the nature of metaphor is to use a kind of thing to explain and experience another kind of thing. However, in some cases, this has great social arguments, meaning that the language investigations used when talking about nuclear weapons have a variety of different discourses used in the different times to make the public acceptable and understandable [6]. It can also be judged, only by metaphor that the contents of fundamental scientific theories can be understood.
b) The second characteristic is that a metaphor that is a cognitive mechanism including a domain that is partially "mapped" to another domain.
The domain mapped is called the source domain (SD) and the domain to map the impact to is the target domain (TD). In other words, a metaphorical expression which is an external expression of conceptual metaphors contains both SD and TD. For example, we can consider the SD and TD of the conceptual metaphor of FEELING in the view of CL.
Source domain: feeling through contact Target domain: abstract concept of intimacy We can see the following example in Vietnamese: (6) Chúng tôi thấy ấm áp trước sự chào đón của cô ấy (We feel warm in her welcome).
From there, we can see that for any metaphors, we can also identify the source domain and target domain. The source domain is usually quite specific experiences and the target domain is more abstract [6]. To understand a CM is to understand the mapping scheme of a source-target domain pair. According to the CL view, metaphor is not only a method of shifting meaning based on the similarity between two things in the metaphor "A is B", but a mapping based on the corresponding points; that is, in the source domain with point A, there will be A mapping in the target domain B [6]. Metaphor is not a language problem but a matter of thought and awareness where map mapping is essential, language is secondary [4]. We often project one-dimensional image diagrams of understanding from a more experienced source domain to understand a less experienced target domain [6]. In Vietnamese, people approach theses aspects of the view of CM, in detail, to produce a range of metaphorical expressions from basing on HSs which are expressed naturally in their language.
c) The third characteristic is that conceptual metaphors are systematic when people use metaphorical expressions systematically.
Lakoff argued that conceptual metaphor reflects a general principle that belongs to the conceptual system hidden behind the expressive language [4].

) Cái nhìn lạnh lẽo từ đôi mắt cô ấy làm tim tôi thắt lại (The cold look from her eyes made my heart tighten). (9) Hắn nhìn chị, cái nhìn vừa gần gũi vừa xa vắng (He looked at her with a both close and very far look).
In fact, conceptual metaphor has included systematic metaphorical terms, reflecting a general principle that belongs to the conceptual system hidden behind the expressive language. These expressions can be interpreted as follows: People use body parts to symbolize, express emotions, but in particular the eyes (sight). Visual upward of eyes (swirling) symbolizes anger rising, feeling through visual contact shows the general sense of human emotions. Emotion is not considered to be good with visual expressions in these situations that listeners feel (cold, cheeky, close, far away), intimacy can be thought about warmth.
d) The fourth characteristic is that there is embodiment in metaphor.
According to Lakoff and Johnson, the first hypothesis of embodiment is the metaphorical process [6]. They also argued that the above translation of the word group just feels like it was led in the examples 7-9 above, derived from human experiences. In the case of the sense of taste, through experience of their body parts, people express in their words. In other words, they based on the sense of taste with its characteristics to express what they think. We consider the following contents. (12) Lời cô ấy ngọt ngào (Her words are sweet). As stated, the view of embodiment is the foundation for thinking so in these situations the sensory experience is considered a 'source' domain to represent other 'target' attributes. The word "đắng chát" (bitter and acrid) that means 'unpleasant tastes in the mouth making our tongue seize' indicates the experience of taste [15]. However, in (10), "đắng chát" indicates a notion of its life uncomfortable, experiencing as an unpleasant feeling. Through experience, people have seen, perceived and thought about the feelings they experienced through taste. In life, when people fail or suffer, they all have the feeling of discomfort. Similarly, the word "ngon" (delicious) which means 'to enjoy the mouth when eating' [15], so in the example (11), we see the metaphor based on the taste created. In this situation, the traders are very interested in the bait (land) and they enjoy 'eating' it. Also, the word "ngọt" (sweet) means 'gentle, pleasant' [15]. In (12), "her words are sweet" with the notion of words which are very easy to hear, making the listener pleasant. Therefore, it is possible to understand that the embodiment is the process of interaction between individuals and the outside world. What our bodies experience in the process of interacting with the environment, society has created the basic foundation for all that we think, understand, behave and communicate [6].
In Vietnamese, to express conceptual metaphors, language users can also use a sense to conceptualise the other senses such as vision -hearing, vision -smell, touch -taste, hearing -taste, smell -vision, etc. These cases make the conceptual metaphors based on HSs in Vietnamese more various, attractive and complex for their users in studying characteristics of CM.

Conclusion
To sum up, with the theoretical foundations of the CL view of the metaphor presented, once again confirms the importance and necessity to approach linguistic analysis according to CL theory, a modern linguistic tendency. In Vietnamese, in CL's view, metaphors have a system of ideas that people use to interpret words in everyday life. They use conceptual metaphors in a way that think or conceptualize the "target" domain through the "source" domain. In experiencing human experiences and the systematic nature of human, people use metaphorical words systematically. For language teaching in general, if the teacher has an in-depth understanding of the metaphor according to the CL points of view, it can help the foreign language learners get particular benefits in learning linguistics by applying the characteristics of conceptual metaphors in Vietnamese. Besides, it is possible to create words to create conceptual metaphors, contributing to the creation of meaning of words. That also supports learners of Vietnamese in approach the meanings more effectively.