The following are some of the chief differences between O. Nhb. and W. S:
1. Preference in O. Nhb. for _a_ in many cases where W. S. has _e_.
2. _A_ sometimes appears in closed syllable where W.S. has æ.
3. _A_ before _l_ + consonant is not broken to _ea_ (Sievers §121.3, and Lindelöf: Die Sprache des Durham Rituals).
4. _A_ before _r_ + consonant very frequently not broken, cp. _arm_, _farra_. Breaking occurs more often, however.
5. _E_ before _l_ + consonant not broken in the Ritual (see Lindelöf).
6. _E_ before _r_ + consonant is broken and appears as either _ea_ or _eo_, cp. _eorthe_, _earthe_.
7. _A_ before _h_, _ht_, _x_ (_hs_) becomes _æ_. Sievers §162.1. In W.S. _a_ was broken to _ea_, cp. O. Nhb. _sax_, W.S. _seax_. This Lindelöf explains as due to the different quality of the _h_--in W.S. it was guttural, hence caused breaking; in Nhb. it was palatal and hence the preceding _a_ was palatalized to _æ_.
8. Nhb. umlaut of _o_ is _œ_. In W. S. it was _e_, cp. _dœma_, _sœca_, W. S. _dēman, sēcan_. See Sievers §§27 and 150.4. Bouterwek CXXVII, and Lindelöf. This difference was, however, levelled out, Nhb. _œ_ becoming also _e_, according to Sievers.
9. Special Nhb. diphthongs _ei_, _ai_, cp. _heista_, _seista_, W.S. _hiehsta_, _siexta_.
10. Influence of preceding _w_ was greater than in the South. A diphthong whose second element was a dark vowel was simplified generally to a dark vowel (Lindelöf), e.g., _weo_ > _wo_, _wio_ > _wu_, cp. _weorld_ > _world_, _weord_ > _word_, etc.
11. W.S. _t_ is represented quite frequently by _ð_ or _d_, regularly so when combined with _l_, often so when combined with _s_. See Lindelöf above.
12. W.S. _ð_ frequently appears as _d_ in the North; the reverse also occurs. See Bouterwek CXLII-CXLV. In a few cases _ð_ > _t_.
13. _C_ before _t_ where W. S. regularly has _h_. See Bouterwek.
14. Metathesis of _r_ less extensive than in W. S.
15. Preceding _g_, _c_, _sc_ did not cause diphthongation in Nhb. as often as in W. S.
16. Generally speaking, less extensive palatalization in Nhb. than in W. S.
17. Dropping of final _n_ in infinitives in Northumbrian.