Generally speaking，a translator is not supposed to change the "parts o£ speech" of the original work at will. However, the fact that Chinese and English are two entirely different languages determines that in doing translation he should not follow the "parts of speech" of the original mechanically. As a matter of fact, a word in one language belonging to a certain "part of speech" has often to be converted into a different "part of speech" to conform to the usage of the language to be translated into. And this is essentially what "conversion" means.
"Conversion" is one of the most important translation techniques. It is necessitated primarily by the difference in syntactic structure and idiom of the two languages---Chinese and English. Moreover, "conversion" on the basis of an accurate comprehension, has Long been accepted as one of the techniques essential to improving the quality of our version.
1. English nouns converted into Chinese verbs.
In this connection, we should like to point out further that the wide use of nouns is a peculiar feature of English when compared with Chinese. On many occasions it is not difficult for us to notice that a certain idea or concept which is expressed in the verb form in Chinese, is usually expressed in the noun form in English. Hence comes the necessity of "conversion". e.g.
"The trend towards faster and larger airliners continues."——“客机继续向着大型和高速发展。”
“Another innovation will be the use of variable geometry——the wings will have two positions. "——“另一项创新是使用变几何形状布局,即机翼可有两个位置。”
“In the course of this review of the progress of light we also seek to indicate the general relations of the theory of light to other departments of science, ”——“在这样回顾光学理论进展的过程中，我们也力求指甬光学理论同其他学科的一般联系。”
2. English adj. , prep, or prep, phrases converted into Chinese verbs, e. g.
"They buy plastic articles because their smooth surfaces are so easy to keep clean, ..."——“因为塑料制品的表面光滑，很容易保持清洁，所以，人们购买塑料制品。”
“At subsonic speeds the solid tunnel walls do not allow the spread of the streamlines around the model which would occur in flight, and consequently there is a distorted flow field.”——“在亚声速下,风洞实壁不允许模型周围的流线像在飞行中那样迸行扩张，固而使流场发生畸变。”
3. The“passive” converted into the “active”，