crossed the category borderline, the new word automatically acquires all the properties of the new category, so that if it has entered the verb category, it is now regularly used in all the forms of tense and it also develops the forms of the participle and the gerund. Such regularity can hardly be regarded as indicating a mere functional change which might be expected to bear more occasional characteristics. The completeness of the paradigms in new conversion formations seems to be a decisive argument proving that here we are dealing with new words and not with mere functional variants. The data of the more reputable modern English dictionaries confirm this point of view: they all present converted pairs as homonyms, i. e. as two words, thus supporting the thesis that conversion is a word-building process.
Conversion is not only a highly productive but also a particularly English way of word-building. Its immense productivity is considerably encouraged by certain features of the English language in its modern stage of development. The analytical structure of Modern English greatly facilitates processes of making words of one category of parts of speech from words of another. So does the simplicity of paradigms of English parts of speech. A great number of one-syllable words is another factor in favour of conversion, for such words are naturally more mobile and flexible than polysyllables.
Conversion is a convenient and "easy" way of enriching the vocabulary with new words. It is certainly an advantage to have two (or more) words where there was one, all of them fixed on the same structural and semantic base.
The high productivity of conversion finds its reflection in speech where numerous occasional cases of conversion can be found, which are not registered by dictionaries and