To write an essay is not only a problem of what to write, but how to write, and it is a systematic engineering. It is well know that, in convention, vocabulary, grammar and texture are three key problems of writing, so if we can grasp the correct usage of them, it is possible to write a fit composition. But we all have the experience that although we have recited so many vocabularies, we still cannot write a brief, precise and strict essay. Why?
With the help of the contemporary achievements of linguistics, we have known that it is crucial to an excellent works such as the choice of words, the relevance of words in context, the arrangement of situation of things, the patterns of narration, the bonds of clauses, and the nominalization structure. Here we will discuss these new concepts of writing.

1. The choice of words
We should know that there are two types of words in English, one comes from Anglo-Saxon, the other from Latinate. In the oral context, we often use the former, because, they are more easy to understand. Conversely, when we write an essay, we had better use the later, for they are more graceful and formal. The two types are also problems of style, one is informal, and the other is formal. We should know that the readers of our compositions are English teachers, and they are experts owning much knowledge of the world, therefore we should improve the formal degree of composition. Here is a comparison between them.
Latinate Anglo-Saxon
Accomplish Do
Additional Extra
Assistance Help
Cessation Stop
Application Use
Commence Begin
Considerable Much
Concerning About
Indicate Show
Inquire Ask
Similar to Like
Vulnerable Weak
Prior to Before

2. The relevance of words in context
Fluency English (FE) is our pursuing aim. A characteristic of FE is the relevance of the words in clauses. This relevance can produce a main line in the text so that it can assist reader to understand the meanings of the passage more easily. There are many relevant methods such as simple lexical repetition, complex lexical repetition, hyponymic repetition (or genus-species repetition), co-reference repetition. And we should avoid the simple repetition from word to itself; we should utilize those deliberate repetitions in our composition.

3. The arrangement of situation of things
The arrangement of situation of things is a concept of texture, here we will not discuss it detailed but pose a usual arrangement method, and we defined it as SCR (Start-Consequence-Result). The SCR can be used in the many literature genres, it is the key of the SCR that we should put the important information in the former scene, and we arrange the unimportant information (common information) in the later scene. Also we can say that we arrange the important information in the stem clause and unimportant information (common information) in the affiliated clause.

4. the patterns of narration
Here narration is a concept of wide meaning, it includes narration, illustration, disputation etc. Frequently we use disputation in the composition of GEE (graduate entrance exams). There are three major patterns we can extend our topic with its relevant raw materials: question-answer pattern, claim-counterclaim pattern, and general-specific pattern. Any of them can help us organize our texture efficiently.

5. The bonds of clauses
When we produce a passage we should use many clauses surrounding our topic, the relations among those clauses are the bonds of clauses or the linking of the clause. We can divide the clauses into two types: central sentence and marginal sentence. The former initiates a topic or concludes a result, and the later supplies some materials to make examples illustrate the topic.
Here are some general linking words or phrases, they are attributed to referential connectives and logical connectives, such as and, also, and then, in addition, furthermore, moreover, then, therefore, it follows that, accordingly, thus, hence, so, for example, for instance, namely, that is, but, whoever, nevertheless, on the contrary, whereas, conversely, frequently, in other words, in conclusion, to sum up, to summarize, all in all, and so on.

6. The nominalization structure(NS)
NS is a surface expression of clause, it is a derivative of verb or adjective. It has a classic suffix such as –ability, -ity, -ness, -ment, -ship, -ation, for instance, arrangement, possibility, dynasty, leadership, carefulness etc.
NS has four major rhetorical functions, which are concision, precise, objectivity, and strictness. With the assistance of NS, we can detailedly express the true meanings.
Although the NS is very useful for writing, it is extremely difficult to grasp it freely. And it is a pity that many books of high English teaching omit the NS, even in the prevalent book <>(Analyzing the long & difficult clauses in translating and reading).

From the above discussion we can see that there are many key points in writing, we should study them through hard work, and, as the saying that swimming should be learnt through swimming, fluency English composition should be written through writing.