ō .. ē:—sōhte (sought prt.), sēċan (to seek); fōda (food), fēdan (to feed).
ēa .. īe:—hēawan (to hew), hīewþ (hews); tēam (progeny), tīeman (teem).
ēo .. īe:—stēor (rudder), stīeran (steer); ġe·strēon (possession), ġes·trīenan (gain).
Before proceeding to gradation, it will be desirable to describe the other most important vowel-relations.
a, æ, ea. In O.E. original a is preserved before nasals, as in mann, lang, nama (name), and before a single consonant followed by a, u, or o, as in dagas (days), dagum (to days), faran (go), gafol (profit), and in some words when e follows, as in ic fare (I go), faren (gone). Before r, l, h followed by another consonant, and before x it becomes ea, as in heard (hard), eall (all), eald (old), eahta (eight), weaxan (to grow). Not in bærst (p. [7]). In most other cases it becomes æ:—dæġ, (day), dæġes (of a day), fæst (firm), wær (wary).
e before nasals always becomes i: compare bindan (to bind), pret. band, with beran (to bear), pret. bær.
e before r (generally followed by a consonant) becomes eo:—eorþe (earth), heorte (heart). Not in berstan (p. [7]). Also in other cases:—seolfor (silver), heofon (heaven).
i before r + cons. becomes ie:—bierþ (beareth) contr. from bireþ, hierde (shepherd) from heord (herd), wiersa (worse).
ę before r, or l + cons. often becomes ie:—fierd (army) from faran, bieldo (boldness) from beald, ieldra (elder) from eald.