Origins
The word 'will' occupies a unique position in English as both a modal auxiliary verb expressing futurity and a noun and verb expressing desire, intention, and determination.βββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ Both uses descend from Old English 'willan' (to wish, to desire, to want, to be willing), from Proto-Germanic *wiljanΔ , from PIE *welhβ- (to wish, to will, to choose).
The semantic development from desire to future tense is one of the most well-documented grammaticalization paths in historical linguistics. In Old English, 'willan' was purely volitional β it expressed what the subject wished or intended: 'ic wille gΔn' meant 'I wish to go' or 'I intend to go,' not 'I am going to go.' But statements of intention inherently imply futurity (if I intend to go, then my going lies in the future), and over the Middle English period, the volitional meaning faded and the future meaning became primary. By the Early Modern period, 'will' had become the standard future tense marker, though traces of volition persist in constructions like 'Will you help me?' (are you willing?) and 'He will insist on doing that' (he persists in wanting to).
The PIE root *welhβ- produced a rich family across the Indo-European languages. Latin 'velle' (to wish, to want) and its nominal derivative 'voluntΔs' (will, willingness, desire) gave English 'voluntary' (done by wish), 'volunteer' (one who acts by choice), 'volition' (the act of willing), 'benevolent' (well-wishing β bene + volens), and 'malevolent' (ill-wishing β male + volens). Through Germanic, the root produced the noun 'will' (desire, determination, testament), the adjective 'willing,' and the adverb 'well' (from Proto-Germanic *wel, in a wished-for manner, satisfactorily). 'Wealth' is from Middle English 'welthe,' formed from 'well' + the abstract suffix '-th' β literally 'the condition of faring well,' meaning prosperity or abundance.
Modern Usage
The distinction between 'will' and 'shall' as future markers has a complex history. In traditional prescriptive grammar, 'shall' expressed simple futurity in the first person ('I shall go') while 'will' expressed determination ('I will go means I am determined to go'), with the roles reversed in the second and third persons. This distinction, codified by 17th-century grammarians, probably never reflected actual widespread usage and has largely collapsed in modern English, where 'will' serves as the default future marker for all persons and 'shall' survives mainly in formal, legal, or British English contexts.
Old English 'willan' was a preterite-present verb β a class of verbs whose present-tense forms were historically past tenses of strong verbs, giving them irregular conjugation patterns. This explains the anomalous past tense 'would' (from Old English 'wolde'), which functions today both as the past of 'will' and as a conditional marker ('I would go if I could'). The conditional use of 'would' parallels the future use of 'will' β both derive from volitional meanings that have been grammaticalized into tense and mood markers.