778. With regard to the formation of verbs there remains nothing to be added to what has been already said regarding the structure of roots and the classes of verbal bases (§. 109a.) which proceed thence, and subsequently respecting the formation of derivative verbs. The primitive pronouns, and the appellations of numerals, do not follow the ordinary rules for the formation of words (see §. 105.), and, with their derivatives, are discussed in the paragraphs allotted to them. We shall now discuss simply the formation of substantives and adjectives; and, first, those which stand in close connection with the verb, and, both in the organization and in the application of language, play a very important part: we allude to the participles and the infinitive. It might be said that we ought to treat of the formation of nouns before treating of their inflection, because words must be formed before they are inflected. But for practical considerations it appeared more useful, at first, only to lay down the principle of the formation of words generally, as is done in §§. 110. 111., and to defer the more full investigation of the subject to this place. At all events, the theory of the formation of tenses must precede that of the participles, as the latter; for the most part, irrespective of their nominal suffixes, rest on a principle of formation similar to that of the corresponding tenses of the indicative, and bear a sisterly, if not a filial relation to them.