GRAMMAR: PARTS OF SPEECH
THE number and description of parts of speech depends on the grammar of a particular language. They correspond partly to the parts of a sentence and are partly determined by the forms and usages of the given language. Hence in the definition of parts of speech as we have inherited them from Classical grammarians sometimes 'logical', sometimes formal criteria are used. The latter, of course, come under the criticism of logicians, but they cannot be neglected in the account of a particular language. If, for instance, a language is so constructed that substantives are each of single gender but adjectives are of several genders so as to agree with the substantives, then it is of no relevance to hold with Viggo Brøndal that the adjective has no justification in morphology, logic, or syntax. Its cases in Latin or Greek are those of the substantive but it has the additional formal property of varying gender which is not possessed by substantives. In the absence of such formal criteria, as in English or Chinese, a given word may be both adjective and a substantive, e.g. Eng. good = Ch. hao3 (OCh. kung.1 . . . Ch'iu2hao3 yu2Chu.1 'the duke sought good [relations] with [the state of] Chu', where hao3 is a noun).
Even in the absence of external marks, however, it can, I think, be affirmed that the distinction between certain parts of the sentence are respected by the parts of speech. There is a broad difference between nouns and verbs, the former abstracted from particular circumstances and named so as to enter into any context, the latter specialized by accompaniments which fit them to express the individual phenomenon. The verb may produce a verbal noun of action or agent but these retain their verbal properties in large part. The noun covers substantives, adjectives, adverbs, and may offer a basis for the creation of conjunctions and prepositions. But between noun and verb there is a frontier, marked by morphemes in many languages and by associations in English. Thus one may say 'my hand'/'I hand (it)' in English, but 'my hands' and 'he hands' have different morphemes in -s (i) plural, (ii) third person singular, and 'he handed', 'he will hand', 'he would have handed' &c., are