Why plural of boy is not Boies

The band of boys to which michael was attached was marched at once to adrianople.:The boy's ball (one boy) the boys' ball (two or more boys) why plural of boy is not boies?'why' questions almost never have a useful answer in relation to language.In order to make possessive form of a plural word, we generally add an apostrophe (') at the end of that word;What's the plural of boy?

The plural of boy is boies.In one of the boys is, one is the singular subject and therefore takes the singular form of the verb to be which is is!The boys, they're over there!:Of the boys is a prepositional phrase and therefore not the subject.Why isn't the plural of boy boies.