There is no dual in the _present_ English. It has been seen, however, that in the Anglo-Saxon there _was_ a dual. But the Anglo-Saxon dual, being restricted to the personal pronouns (_wit_ = _we two_; _git_ = _ye two_), was not co-extensive with the Greek dual. There is no dual in the present German. In the ancient German there _was_ one. In the present Danish and Swedish there is no dual. In the Old Norse and in the present Icelandic a dual number is to be found. From this we learn that the dual number is one of those inflections that languages drop as they become modern. § 197. The numbers, then, in the present English are two, the singular and the plural. Over what extent of language have we a plural? The Latins say _bonus pater_ = _a good father_; _boni patres_ = _good fathers_. In the Latin, the adjective _bonus_ changes its form with the change of number of the substantive that it accompanies. In English it is only the substantive that is changed. Hence we see that in the Latin language the numbers were extended to adjectives, whereas in English they are confined to the substantives and pronouns. Compared with the Anglo-Saxon, the present English is in the same relation as it is with the Latin. In the Anglo-Saxon there were plural forms for the adjectives. § 198. Respecting the formation of the plural, the current rule is, that it is formed from the singular by adding s, as _father_, _fathers_. This, however, is by no means a true expression. The letter s added to the word _father_, making it _fathers_, is s to the _eye_ only. To the _ear_ it is z. The word sounds _fatherz_. If the s retained its sound the spelling would be _fatherce_. In _stags_, _lads_, &c., the sound is _stagz_, _ladz_. The rule, then, for the formation of the English plurals, rigorously, though somewhat lengthily expressed, is as follows.--_The plural is formed from the singular, by adding to words ending in a vowel, a liquid or flat mute, the flat lene sibilant (z); and to words ending in a sharp mute, the sharp lene sibilant (s):_ e.g. (the sound of the word being expressed), _pea_, _peaz_; _tree_, _treez_; _day_, _dayz_; _hill_, _hillz_; _hen_, _henz_; _gig_, _gigz_; _trap_, _traps_; _pit_, _pits_; _stack_, _stacks_. § 199. Upon the formation of the English plural some further remarks are necessary. a. In the case of words ending in b, v, d, the th in _thine_ = ð, or g, a change either of the final flat consonant, or of the sharp s affixed, was _not a matter of choice but of necessity_; the combinations abs, avs, ads, aðs, ags, being unpronounceable. b. Whether the first of the two mutes should be accommodated to the second (aps, afs, ats, aþs, aks), or the second to the first (abz, avz, adz, aðz, agz), is determined by _the habit of the particular language_ in question; and, with a few _apparent_ exceptions it is the rule of the English language to accommodate the second sound to the first, and not _vice versâ_.