Do not – Donβt
Cannot – Canβt
Are not – Arenβt
Would not – Wouldnβt
Will not- Wonβtβ¦ but why is not Willnβt ?
βWillβ comes from Old English willan (to want / to intend). Its negative form back then was nyllan (βnot-willβ). Example: ic nelle = βI will not.β Over time, nyllan disappeared from common use. Instead, people just said βwill not.β
Contractions in English follow sound ease, not strict logic. βWillnβtβ is hard to say (your tongue has to bounce awkwardly between the βlβ and βnβ). βWonβtβ is smoother, so it won the battle of usage. Middle English had wyll not β wynnot β wonnot β wonβt. That βoβ in wonβt is basically a leftover vowel shift from the 15thβ16th century. Think of it like βainβtβ β not logical, but it stuck because it was easier to say.
So the short answer:
It was once closer to willnβt (like will not β wynnot), but English speakers preferred smoother, faster sounds. That is why we got wonβt.