Easy examples occur in A.S. bān, M.E. boon (baon, bòòn), mod. E. bone; as contrasted with Icel. bōn, M.E. boon (boon, bóón), mod. E. boon (buun). In other words, the mod. E. bone was pronounced in M.E. so as to rime with lawn; whilst the mod. E. boon was then pronounced so as to rime with lone.
A few exceptions occur, shewing occasional relaxations of the general rule. They are doubtless due, as Ten Brink suggests, to a paucity of rimes in some particular ending. Thus, when the long o is absolutely final, as in go (gao), do (doo), Chaucer considers these as permissible rimes, and pairs them together freely; and owing to such usage, we even find agoon (agaon) riming with doon (doon) in Troilus, ii. l. 410. But this is the only instance in Troilus of this character; in all other places, the ending -oon relates to the open o; the riming words being alloon, anoon, atoon, boon (bone), foon (foes, A.S. fan), goon, noon, stoon; to which add roon, it rained, woon, quantity. In the Cant. Tales, B 3127, we find the rime dōm, doom, hōm, home; but words in -ōm are, of course, extremely scarce, so that there was little else to be done. For a like reason, sooth (sooth) sometimes rimes with wrooth (wraoth), Bk. of the Duchesse, 513, 519, 1189; and sothe (soo·dhə) with bothe (bao·dhə), Sec. Nonnes Tale, G 167; Troil. iv. 1035.
With these few exceptions, the rule of distinguishing the two qualities of o is rigorously observed. Thus we find in Troilus, rimes in -òòt, viz. hoot, noot, woot, wroot, A.S. hāt, nāt, wāt, wrāt, ii. 890, 1196, iv. 1261. And we find, on the other hand, rimes in -óót, viz. foot, moot, soot, A.S. fōt, mōt, sōt, iii. 1192. Once more, we find, in the same poem, rimes in -òte, viz. hote, note, grote; cf. A.S. hāte, adv., A.F. note (Lat. nŏta), O. Friesic grāta; iv. 583. And yet again, there are rimes in -óte, viz. bote, fote, rote, sote, from A.S. bōt, fōt, Icel. rōt, A.S. swōte, adv.; ii. 345, 1378, v. 671, 1245. Every one knows the first rime in the Cant. Tales, that of sote, rote, (pronounced as mod. E. soata, roata)[[29]].
[§ 30]. Open and close ē. In like manner, Chaucer distinguishes to some extent, and with certain rather more numerous
exceptions, between the open and close long e. This is a somewhat more intricate matter, so that it is best to give the results succinctly. It is also a little more difficult to follow, because modern English has confused the sounds; though they are frequently distinguished by a different mode of spelling, the old open e being represented by ea, and the old close e by ee. A good example occurs in the case of the words sea and see. The former, in Chaucer, is (sae) or (sèè), with long open e; whilst the latter is (séé), with long close e. Both were written see in M.E.; with the result, that the words were spelt alike at that time, though pronounced differently; but are spelt differently now, though pronounced alike. The difference in spelling is due to an Elizabethan habit, when the two sounds were purposely distinguished; and it may be remarked that such words as are spelt with ea are precisely those which still have a peculiar pronunciation in Ireland. Some writers try to denote this by using such spellings as say, tay, baste, mate, and the like, instead of the standard English sea, tea, beast, meat.
[§ 31]. Stable and unstable ē. The two kinds of ē are best understood by observing their sources.
Before we can shew these clearly, it is necessary to observe that the A.S. ǣ has two values, which must be carefully distinguished. The first, which I shall call 'stable ǣ,' because it regularly produces an open ē in M.E., answers to Germanic and Gothic ai, and is generally due to mutation. Thus hǣlan, to heal, answers to Goth. hailjan, and is mutated from hāl, whole, Goth. hails. This produced M.E. hēlen (haelən), with open ē. Again, M.E. sprēde, to spread (note ea in the modern form), answers to a Gothic *spraidjan[[30]]; for, although no such Gothic form actually occurs, we can infer it from comparison with the G. spreiten; cf. G. heilen with Goth. hailjan above.
The second kind of ǣ, which I shall call the A.S. 'unstable ǣ,' because it occurs in forms which are treated both ways in Chaucer, answers to an original Germanic ǣ, Goth, ē, and does not arise from mutation, though it may arise from gradation. Thus the M.E. dēde, deed, A.S. dǣd, answers to Goth. gadēds, a deed, G. That; and the contrast between the vowel in G. That and that in G. heilen, to heal, is very clearly marked. It is from words of this class that some trouble arises.
[§ 32]. If we inquire further, why there should have been any difference of development in such cases, and how the same form could, apparently, yield both an open ē and a close one, I believe that a clear answer can be given. For it is precisely in such cases that we find different forms in the Old Mercian (or Midland) dialect and in the A.S. (or Southern). Thus, whilst the A.S. (Southern) form of 'deed' was dǣd, the Mercian form was dēd. In fact, the mod. E. deed is clearly Mercian, and that is why it is not spelt with ea in Elizabethan English. Hence Chaucer had, ready to his use, two forms of this word. One was the Southern dèèd, with open ē, from A.S. dǣd; the other was the Midland dééd, with close ē; and, as the Midland dialect was then rapidly gaining the ascendency, he could hardly go wrong if he sometimes used the more popular form. Chaucer knew nothing of etymology, but he knew how words were pronounced by his cotemporaries; a fact which sufficiently explains his habits.