I can promise you that 'shall' and 'will' in contract language can cause many an hour of meetings.
That's because the English language evolved. Years ago, in countries where English was taught using the UK model, shall was used as an absolute; will was a probability.
Contractions are rarely used in formal writing, but they are phun to use!
Disrespect(ful) used to be a noun or an adverb, but within the past ten or fifteen years has became a verb.
What used to be, "The disrespect he demonstrated was unsettling." has become, "He disrespected me, and that's unsettling."
or, "Don't be so disrespectful!" has become, "Don't disrespect me!"
Then there's Ebonics. Yo.