"-ize" is the common AmE suffix, while in BrE "-ise" is more commonly used:

-ize:

• word-forming element used to make verbs, Middle English -isen, from Old French -iser, from Late Latin -izare, from Greek -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached.

• English picked up the French form, but partially reverted to the correct Greek -z- spelling from late 16c. In Britain, despite the opposition to it (at least formerly) of OED, Encyclopaedia Britannica, the "Times of London," and Fowler, -ise remains dominant.

• Fowler thinks this is to avoid the difficulty of remembering the short list of common words not from Greek which must be spelled with an -s- (such as advertise, devise, surprise).***

(Etymonline)

optimise vs optimize usages in AmE vs BrE.

𝑇𝐿;𝐷𝑅

'Wind' (n) and 'wind' (v) had the same vowel in Old English. Both had a short vowel /i/ which was lengthened in Late OE due to a sound change triggered by consonant clusters such as /nd, ld, mb, rd/ etc. The vowel in 'wind' (n) got shortened in the seventeenth century for some reasons. The short and long vowels in 'child' and 'children' can also be attributed to the same sound change.

𝐻𝑜𝑚𝑜𝑟𝑔𝑎𝑛𝑖𝑐 𝐿𝑒𝑛𝑔𝑡ℎ𝑒𝑛𝑖𝑛𝑔

By about the tenth century (Late Old English), there was a sound change called Homorganic Lengthening (HL) through which original short vowels were lengthened in certain words in the environment of a following voiced homorganic cluster. To be precise, before a cluster of Sonorant (Nasal or Liquid) + voiced homorganic obstruent.

Homorganic means having the same place of articulation, so vowels before clusters like /nd/, /ld/, /mb/, /rd/, /rn/, /ŋɡ/ etc., were lengthened in certain words. The change also applied to some clusters with /r/ as their first element such as /rd/, /rn/, /rl/, /rð/ (Donka Minkova) so the vowel in words like board, hoard, yearn, earl, earth etc., were also lengthened due to HL.

Examples

• A striking example of HL is the word 'climb': Old English climban and would've been pronounced with a short vowel before HL: /ˈklim.bɑn/, it became: /ˈkliːm.bɑn/¹
• 'Ground' was OE grund, pronounced /ɡrund/, it became /ɡruːnd/²
• 'Blind' was OE blind, pronounced /blind/, it became /bliːnd/
• 'Field' was OE feld, pronounced /feld/, it became /feːld/³

Influence of a third consonant

However, the lengthening didn't take place when the homorganic cluster in question was followed by a third consonant. It means HC+C ('HC' being the homorganic cluster and 'C' another consonant) cluster was impervious to HL. This can be illustrated by the following example:

• 'Hound' was OE hund and pronounced /xund/, it became /xuːnd/. 'Hundred', on the other hand, was hundred, pronounced /ˈxundred/, it didn't change because the homorganic cluster /nd/ was followed by a third consonant /r/.

The vowel in 'grind' is long due to HL and that of 'grindstone' (ModE: /ˈɡraɪn(d)stəʊn/) should've been short because the /nd/ is followed by a third consonant, but it isn't. Otto Jespersen says that 'grindstone' was formerly always /ˈgrinstən/ and the long vowel in ModE is by analogy with 'grind'.

This point also accounts for the long and short vowels in 'child' and 'children'.

Child vs children

• 'child' was OE ċild, pronounced /t͡ʃild/, it became /t͡ʃiːld/
• 'children' was OE ċildru, pronounced /t͡ʃildru/, it didn't undergo the sound change because the cluster /ldr/ was impervious to HL.

Don't let the w[ɪ]nd w[aɪ]nd you up

There are different assumptions as to why the vowels in 'wind' (v) and 'wind' (n) are different:

• Donka Minkova says 'the pair wind - wind is a special case, probably best explained on the grounds of homophony avoidance'.
• Jeremy Smith says that this is a sporadic instance of HL where it failed. He goes on to say '[t]his distinction may be the result of a disambiguating choice between variant pronunciations to avoid confusion between two meanings'
• Otto Jespersen says that the noun wind used to have /iː/, but it got shortened by analogy with frequent compounds such as windmill (also OED), window which had short vowels.
• OED and A History of Modern English sounds and morphology by Eilert Ekwall say that the short vowel is due to analogy with windy.

This was a sporadic sound change and only affected certain words. There are many, many words that have a 'voiced homorganic cluster' at the end, yet they have short vowels: band, hand, land, dumb, lamb, sand, send, held, bend, blend, end, rend, send, spend, wend etc. (Minkova)

Notes

1. The nasal endings (/ɑn/) were later on lost. The reason 'climb' has /aɪ/ (instead of /iː/) in ModE is because of the GVS.
2. /uː/ to /aʊ/ shift is also because of the GVS.
3. /eː/ to /iː/ shift can also be ascribed to the GVS.

Abbreviations

• HL: Homorganic Lengthening
• OE: Old English
• ME: Middle English
• ModE: Modern English
• OED: Oxford English Dictionary
• GVS: Great Vowel Shift

References

• A Historical Phonology of English by Donka Minkova
• Modern English Grammar on Historical Principles by Otto Jespersen
• A History of Modern English sounds and morphology by Eilert Ekwall
• Oxford English Dictionary
• Sound Change and the History of English by Jeremy Smith
• Old English: A Historical Linguistic Companion by Roger Lass