_-es_ has come to be the
"standard" ending; that is, whenever we adopt a new word, we make its
plural by adding _-s_ or _-es._

I. Plurals formed by the Suffix _-en_.

[Sidenote: _The_ -en _inflection._]

38. This inflection remains only in the word oxen, though it was
quite common in Old and Middle English; for instance, _eyen_ (eyes),
_treen_ (trees), _shoon_ (shoes), which last is still used in Lowland
Scotch. _Hosen_ is found in the King James version of the Bible, and
_housen_ is still common in the provincial speech in England.

39. But other words were inflected afterwards, in imitation of the
old words in _-en_ by making a double plural.

[Sidenote: -En _inflection imitated by other words._]

Brethren has passed through three stages. The old plural was
_brothru_, then _brothre_ or _brethre_, finally _brethren_. The
weakening of inflections led to this addition.

Children has passed through the same history, though the
intermediate form _childer_ lasted till the seventeenth century in
literary English, and is still found in dialects; as,--

"God bless me! so then, after all, you'll have a chance to see
your _childer_ get up like, and get settled."--QUOTED BY DE
QUINCEY.

Kine is another double plural, but has now no singular.

In spite of wandering _kine_ and other adverse
circumstance.--THOREAU.

II. Plurals formed by Vowel Change.

40. Examples of this inflection are,--

man--men
foot--feet
goose--geese
louse--lice
mouse--mice
tooth--teeth

Some other words--as _book_, _turf_, _wight_, _borough_--formerly had
the same inflection, but they now add the ending _-s_.

41. Akin to this class are some words, originally neuter, that have
the singular and plural alike; such as _deer_, _sheep_, _swine_, etc.

Other words following the same usage are, _pair_, _brace_, _dozen_,
after numerals (if not after numerals, or if preceded by the
prepositions _in_, _by_, etc, they add _-s_): also _trout_, _salmon_;
_head_, _sail_; _cannon_; _heathen_, _folk_, _people_.

The words _horse_ and _foot_, when they mean soldiery, retain the
same form for plural meaning; as,--

The _foot_ are fourscore thousand,
The _horse_ are thousands ten.
--MACAULAY.

Lee marched over the mountain wall,--
Over the mountains winding down,
_Horse_ and _foot_, into Frederick town.
--WHITTIER.

III. Plurals formed by Adding -s or -es.