Language family is a group of language related by descent from a common ancestor, called the proto-language of that family.
Here are some of the major language families in the world:
- Indo-European languages (Europe, Southwest to South Asia, America, Oceania)
- Sino-Tibetan languages (East Asia)
- Niger-Congo languages (Sub-Saharan Africa)
- Afro-Asiatic languages (North Africa to Horn of Africa, Southwest Asia)
- Austronesian languages (Oceania, Madagascar, maritime Southeast Asia)
- Dravidian languages (South Asia)
- Altaic languages (Central Asia, Northern Asia, Anatolia, Siberia)
- Austro-Asiatic languages (mainland Southeast Asia)
- Tai-Kadai languages (Southeast Asia)
- Japonic languages (Japan)
According to these, English belongs to Indo-European language, and Vietnam belongs to Sino-Tibetan language, Austronesian language, Austro-Asiatic language and Tai-Kadai language.
Morphological typology is a way of classifying the languages of the world (that groups languages according to their common morphological structures.
1. Analytic languages
In analytic languages, there is generally little if any morphological changes. Grammatical changes are indicated by word order, or by bringing in additional words. Words are usually meaningless on their own, or they just indicate the root concept. In these languages' grammars, context and syntax are more important than morphology.
Analytic languages include some of the major East Asian languages, such as Chinese, and Vietnamese. Additionally, English is moderately analytic (probably one of the most analytic of Indo-European languages). However, it is traditionally analyzed as a synthetic language.
2. Synthetic languages
Synthetic languages tend to make lots of changes to words by adding morphemes. The morphemes might or might not be distinguishable from the root. Word order is less important, as it is the morphemes that give the meaning of the words in the sentence. In addition, there tends to be plenty of concordance (cross-reference between different parts of the sentence, agreement). In synthetic languages' grammars, morphology tends to about as important as context and syntax.
Most Indo-European languages are moderately synthetic.
There are two subtypes of synthesis, according to whether morphemes are clearly differentiable or not. These subtypes are agglutinative and fusional (or inflectional or flectional in older terminology).
Russian is an example of a synthetic language.
2.1 Agglutinative languages
Agglutinative languages have words containing several morphemes that are always clearly differentiable from one another in that each morpheme represents only one grammatical meaning and the boundaries between those morphemes are easily demarcated; that is, the bound morphemes are affixes, and they may be individually identified. Agglutinative languages tend to have a high number of morphemes per word, and their morphology is highly regular.
Agglutinative languages include Korean, Hungarian, Turkish, and Japanese.
2.2 Fusional languages
Morphemes in fusional languages are not readily distinguishable from the root or among themselves. Several grammatical bits of meaning may be fused into one affix. Morphemes may also be expressed by internal phonological changes in the root (i.e. morphonology), such as consonant gradation and vowel gradation, or by suprasegmental features such as stress or tone, which are of course inseparable from the root.
Most Indo-European languages are fusional to a varying degree. A remarkably high degree of fusionality is also found in certain Sami languages such as Skolt Sami.
3. Polysynthetic languages
n 1836, Wilhelm von Humboldt proposed a third category for classifying languages, a category that he labeled polysynthetic. (The term polysynthesis was first used in linguistics by Peter Stephen DuPonceau who borrowed it from chemistry.) These languages have a high morpheme-to-word ratio, a highly regular morphology, and a tendency for verb forms to include morphemes that refer to several arguments besides the subject (polypersonalism). Another feature of polysynthetic languages is commonly expressed as "the ability to form words that are equivalent to whole sentences in other languages". Of course, this is rather useless as a defining feature, since it is tautological ("other languages" can only be defined by opposition to polysynthetic ones, and vice versa).
Many Amerindian languages are polysynthetic. Inuktitut is one example, for instance the word-phrase: tavvakiqutiqarpiit roughly translates to "Do you have any tobacco for sale?".
Note that no clear division exists between synthetic languages and polysynthetic languages; the place of one language largely depends on its relation to other languages displaying similar characteristics on the same scale.