Before I learn sociolinguistics class, I think it is quite difficult to tell what the difference between language and dialect is. But, after I had learned I found out that language is something that mankind use to communicate to each other. Language is a big word. It concludes dialect, vernacular, and so on. Nevertheless, dialect is the language that use only in idiolect, only use in their group. For me, I think that there are many dialects in each country. For example, there are many dialects in Thailand such as dialects of the north, northeast, south and so on. Dialect can divided in to two main points. Firstly, the sociolinguistics used geography to separate each dialect. Secondly, the social class can be factor to divide the dialect.
R.A. Hudson pointed that out it is hard to distinct between ‘language’ and ‘dialect’. The hierarchical model of the family tree indicates that the boundaries between varieties are clear all levels of the tree. We consider the most straightforward variety differences based on geography which is called regional dialects. The dialect geographer had draw a line between the area where one item was found and areas where others were found, showing a boundary for each area called an isogloss. The family tree model can be a very important prediction to be made regarding isoglosses. This prediction follows from the strict hierarchy among varieties in the model. The social class, sexes, and age can impact to dialect too. Dialectologists speak of social dialects or sociolects to refer to non-regional differences. Because of these other factors, a speaker may show more similarity in language to people from the same social group in a different area than to people from a different social group in the same area.
Dialectology is the study of dialect and dialects (Frederick J.Newmeyer, 1995: 119-135). Not surprisingly, the major issues in the field of dialectology during the century of its
References: พัชรี พลาวงศ์ (2534), ภาษาถิ่นในสหรัฐอเมริกา , ภาษาถิ่นในภาษาอังกฤษ The Dialects of English. มหาวิทยาลัยรามคำแหง: สำนักพิมพ์มหาวิทยาลัยรามคำแหง: หน้า 18-104 Frederick J. Newmeyer (eds.)(1995). Linguistics: The Cambridge Survey. New York. University of Cambridge. 119-133 Hudson., R.A.(1988). Sociolinguistics. New York. University of Cambridge.: 37-43