Prithee, good Sires and Maids, why, marry and i'faith 'tis true!
Odsblood, I woulds't fain ne'er use yon befouled and debased form of speech of ye corruptest nature when ye language of Shakespeare can trip lightly from a body's lips!
On the other hand, look, guys and girls, language evolves. It grows, it changes, new words are added, old words fall into disuse (read the OED for a myriad of examples) and to try to fix it into one form is pointless.
So, yes, some of these Americanisms grate on the ear, but short of passing laws like the French have where they have to create a "Frenchified" word like "L'Ordinateur" instead of "Le Computer" just to avoid using an English <pah! spit!> one, which are, frankly, rather silly, it's just something that you'll have to live with.