(2) By changing the root vowel.

(3) By adding _-s_ (or _-es_).

The first two methods prevailed, together with the third, in Old
English, but in modern English _-s_ or _-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.