IntroductionLinguistics is consisted of many aspects, including phonetics, morphology and semantics. In different parts of linguistics, morphology is a very important part, as well as a significant aspect on writting. That's because writting is a type of expression about language, therefore learning and knowing morphology has an important role in English writting.
Definition
Morphology is defined as the study of the internal structure and the formation of words. It is consisted by three aspects, which are words, morpheme and word-formation. And these three aspects are the simplest and most basic things in linguistics.

Classfications
When we study morphology, there are three impotant parts I have mentioned before.First and foremost thing is about word, we know word are the smallest free units of language that unite sounds with meaning, and it is the most important constituent of a sentence, a paragraph even the whole language. The second part is about morpheme, morpheme is a magic object, it is the smallest unit that carries grammatical and semantic meaning, and a word is often consisted by it. Last but not least, word-formation is new object for us, while it is very useful in morphology.
AnalysisWordWord, in every language, has a significant role. It can not only use to both speak and write, but also decide the quality of an essay.Therefore,word is a basic element which connects each of human beings. From different angles, we have various definiations about word. For instance, people regard word as a sound or combination of sounds from phonology, or an important part of sentence, paragraph from structure of passage.Despite the difficulty in defining the concept of word, many linguists have been classified word into three categories.
the first category is open-class words and close-class word. In English, many words like nouns, verbs, adjectives and adverbs make up the largest part of vocabulary. We call it is “open” classes, and open-class words are also formed lexical words or content words. In contrast, the other words, such as pronouns, determiners, conjunctions or prepositions are composed the “close” words. These words are also termed grammatical words or function words[1].

The second category is the lesser categories but very easy to understand and remember, because they arenumerals and interjections.
The last category is variable and invariable words. This type is according to variability. And the distinction of them is about inflection. Variable words can take inflectional ending, while invariable do not[1].

Morpheme
Finished the analyses of words in English, next part is about morpheme. Morpheme is the smallest meaningful unit of language. In English, a morpheme may be a complete word or something else.It may be represented by different formed which called allomorphs. In general, allomorphs can be determined by the phonologically or morphologically conditioned. Moreover,morpheme can be divided into two types, one is free morpheme and bound morpheme, another is inflectional morpheme and derivation morpheme. Morphemes are a small part in linguistics. However, they are important in the word-building process. When we learn how to use a word in one essay, we can make it vivider and more attractive. Apart from these, a good passage is not only need the words that are very complex or deep. on the contrary, it needs many words which can not only adapt it but also easy to understand. Therefore, this is the reason why we should learn word and morpheme.

Word-formation
We have mentioned derivative morpheme in the second point. However, we have not known clearly about what it is and what it belong, and this is the formation of word. In accordance with the introduction of English morphology, word-formation is a process of creating new words by means of existing elements and according to the patterns and rules of a given language[2]. Different from word and morpheme, word-formation can be classified into many different types, such as compounding, derivation and so on. In those many types, nevertheless, there are three main types, which are derivation, compounding and conversion. In my opinion, these types are very useful for us learning how to make our writing more professional and attractive.
Derivation is a kind of word-formation when a new word is formed by adding a derivational morpheme to the root. In English, there are many types of affixation. but all of them can be reduced to both prefixation and suffixation.
Next is compounding. It is one of the oldest and most common ways to form words, and it is a word-formation process consisting of joining two or more bases to form a new unit, a compound word. many people classified it into three categories, which are nouns, verbs and adjective compounds.
Lat but not least one is conversion. Conversion is the process any derivative element, and we can also call it as zero derivation[1]. So far as I know, conversion occurs mostly on some simple words and usually find in words containing one morpheme. And there are some widely categories of conversional, and takes some examples for them:
1、 noun to verb conversion
fishto fish, to fish a dolphin means to hunt a dolphin.

2、 verb to noun conversion
to interest→ interest, I have no interest in writing.

3adjective/ adverb to verb conversion
upto up, to up your head means to put up

4、adjective to noun conversion
nativea returned native
conclusion
Besides, there are the same important types of word-formation I have not mentioned. Although there is not enough time for me to study the complicate and variable linguistics deeply, I have learned much useful knowledge about it in this term. One of interesting part is morphology. Morphology is a small part in the textbook, but it is very important and useful for me. Through the content of morphology, I learned words which are foundation of any language, morpheme that is the smallest linguistic unit and word formation which is a good method to create new words.

These examples and context look very simples, but they are typical. If only we can learn these methods and use them in the right way, we would create a useful and sucessful essay belonging to us.


Reference list


[1]Yang Xingzhang. English Lexicology: A Coursebook. Beijing: Pocket, 2009. Print.

[2]Yang Xingzhang. Li Li. Liu Chengyu. An Introduction to Linguistics. Beijing: Pocket, 2010. Print.

[3]Chen Xinreng. English Linguistics: A Practical Coursebook. Suzhou: Pocket, 2007. Print.