(a) Thus, æ into ea: *hærd (for hard, 7) > heard, hard; *hælf > healf, half; wearð, pret. sg. of weorðan, to become; wealdan, to wield; beald, bold; feallan, to fall; heall, hall; eahta, eight; seah, pret. sg. of sēon, to see.
(b) e into eo (io): weorðan, to become; eorðe, earth; heorte, heart; feorr, far; weorc, work.
e into eo (io) before l+consonant is restricted to l+c or h: meolcan, to milk; seolh, seal. Otherwise the e remains: helpan, to help; swelgan, to swallow; sweltan, to die.
Before h+consonant, and h final: feohtan, to fight; teohhian, to arrange; feoh, cattle.
(c) i into io (eo): stem *hirdio > *hiordi > hierde (i-umlaut), herdsman. *liht (< līht) > lioht, leoht, light, not heavy; Piht, Pioht, Peoht, Pict. *betwīh > betwih, betweoh, between.
Note.—Breaking results from the combination of a palatal vowel (æ, e, i) and a guttural consonant (r, l, h). In passing from the pronunciation of the vowel to that of the consonant, a glide-sound is produced which is a more or less definite guttural vowel. This may be observed in pronouncing well as wœ-al; there as thœ-ar or the-ur; fire as fi-ur or fi-or. It is this glide-vowel that has supplied the second element of these short diphthongs.
10. The palatals g, c, and sc, in the initial position change a following æ into ea; ǣ (=Germanic ē) into ēa; and e into ie (i, y; see 3, Note). (S § 75.)
(a) Thus, æ into ea: *gæf (7) > geaf, gave; *gæt > geat, got; *cæf > ceaf, chaff; Lat. castra > *cæster > ceaster, town; *scæl > sceal, shall; *scæft > sceaft, shaft; *scær > scear, sheared (pret. sg.).
(b) ǣ into ēa: gǣfon > gēafon, gave (pret. pl.); *gǣton > gēaton, got (pret. pl.); Lat. cāseus > *cǣsi > cēasi