_Gemination_ is the doubling of a letter. When final, or next to a
consonant, it is simplified, _mm_ changing to _mb_, _nn_ to _nd_, _ss_
to _st_, _ii_ to _ig_, _un_ to _up_: as, _timbr_ for _timmr_, timber;
_spindl_ for _spinnl_, spindle; _lufast_ for _lufass_, lovest; _lufige_
for _lufie_, love; _bearupes_ for _bearuues_, grove. Double _g_ is
written _cg_, and double _f_, _bb_.
_Umlaut_ is the assimilation of a vowel by the vowel of the succeeding
syllable: _a-umlaut_ changes _i_ to _e_ (_eo_), _u_ to _o_; _i-umlaut_,
_a_ to _e_, _u_ to _y_, _ea_ to _y_, _eo_ to _y_, _á_ to _ǽ_, _ó_ to
_é_, _ú_ to _ý_, _eá_ to _y_, _eó_ to _ý_; _u-umlaut_, _a_ to _ea_ (_o_),
_i_ to _eo_. The _i_ which produces _i-umlaut_ is often changed to _e_ or
dropped: as, _man_, plural _men_, from _meni_; _fót_, plural _fét_, feet,
from _féti_.
_Breaking_ is the change of one vowel to two by a consonant. _G_, _c_,
and _ac_ may break a following _a_ to _ea_, _o_ to _eo_, _i_ to _ie_, _á_
to _eá_, _ó_ to _eó_; _l_, _r_ and _h_ may break a preceding _a_ to _ea_,
_i_ to _eo_ (_io_), _ie_: as, _geaf_, gave; _sceó_, shoe; _sealm_, psalm;
_hleator_, laughter; _meolc_, milk.
_Shifting_ is the weakening of a letter not produced by other letters:
_a_ to _æ_, _ǽ_ to _é_, _eá_ and _eó_ to _é_, etc.; _dæg_, from _dag_,
day.