O.N. _i_ generally remains _i_: _bing_, _grith_, _kist_, _link_, _lite_, _titling_, _wilrone_, frequently written _y_: _byng_, _chyngill_, _gyll_, etc. O.N. _i_ before _st_ > _e_: _gestning_, _restit_. _i_ > _ī_ in _ithand_ (_ythand_), and _ei_ in _eident_.
O.N. _o_ remains _o_: _boldin_, _bolle_, _brod_, _costlyk_, _loft_, _rock_, etc. O.N. _o_ + _g_ > _ow_ in _low_.
O.N. _u_ generally remains _u_: _bught_, _buller_, _clunk_, _cunnand_, _lucken_, _ugg_, _clubbit_, _drucken_, _skugg_. The sound of _u_ in O.N., however, was approximately that of _oo_ in "foot." O.N. _u_ > _ū_ in _drook_.
O.N. _y_ always becomes _i_, written _i_, _y_: _big_, _birr_, _filly_, _flit_, _trig_, _wyndland_, _gylmyr_. The O.N. _y_ had approximately the value of Germ. _ü_.
O.N. _ö_ > _e_ in _gleg_, _glegy_, appears as _u_ in _slut_. O.N. _ö_, _u_-_v_-umlaut of _a_, becomes _æ_, written _a_: _daggit_, _ragweed_, _tangle_. O.N. _ö_, _u_-umlaut of _a_ in originally open syllable, like open _a_, > _ē_ in _spale_.
Hence _u_-umlaut does not appear in loanwords.
O.N. _ja_ > _a_ in _assle-tooth_, _harn_, _starn_. > _e_ in _sker_ and _stern_.
O.N. _jö_ > _a_ in _tarn_. O.N. _jö_ > _i_ before _r_ in _firth_, _gyrth_ (_gjörth_), _gyrthin_.
O.N. _ā_ regularly > _ē_, written _a_, _ai_, _ay_, _ae_, _ei_ (?): _baith_, _blae_, _bray_, _braith_, _fra_, _frae_, _lait_, _craik_, _ra_, _saikless_, _spay_, etc. O.N. _ā_ + _g_ > _aw_, _awch_, _aigh_, _aich_, _awsome_, _law_, sb. _law_, adj. _lawch_, beside _laigh_ and _laich_ in N. Sco. O.N. _ā_ + _l_ > _ow_ in _chowk_ (O.N. _kjálki_).
O.N. _ē_ remains in _ser_, _seir_. _ē_ > _ǣ_, written _a_, in _fallow_. O.N. _ē_ before _tt_ > _i_, written _y_, in _tytt_. Cp. _titt_ in W.Norse dial.
O.N. _ī_ most frequently remains _ī_, written _i_, _y_: _flyre_, _gryce_, _grise_, _myth_, _skrik_, _rive_, _ryfe_, _tithand_, etc. O.N. _ī_ appears as _e_ in _skrech_, probably pronounced _skrich_. O.N. _ī_ > _ē_, written _ei_, in _quey_, _gleit_, _keik_. O.N. _ī_ > _ĭ_ in _scrip_, _wick_, and before original _xl_ in _wissle_ (_wyssyl_). The corresponding word in Norse also has a short vowel, but changed to _e_, _veksl_, _vessla_ (and _versla_).
O.N. _ō_ > _ū_, written _o_, _oo_, _u_, _eu_: _crove_, _rove_, _unrufe_, _hoolie_, _hulie_, _lufe_, _ruse_, _roose_, _sleuth_, _tume_. O.N. _ō_ > _ou_ in _clour_. _ō_ > _oy_ in _toym_ (Bruce), exact sound uncertain. _ō_ + _l_ > _ow_ in _bow_.