Every language if full of clichés, and American English is no exception. As a matter of fact, in its contemporary state as driven by media gobbledygook, American English ranks as the most cliché-ridden language known to Y-H-B.
Some speakers seem to thrive on clichés and other such linguistic detritus. For instance, there is one person, whose speech I regularly overhear, who cannot respond to any interlocutor’s utterances without saying “Wow!” It seems not to matter that there is nothing remarkable in the utterance to which this person is responding with this vocable. Perhaps this sort of speech trait is to be attributed to a species of anosognosia, however non-clinical.
There is no doubt that error born of ignorance is one of the acknowledged causes of language change. However, from a purist’s point of view––which happens to be that of Y-H-B––ignorance of the law (alias code = language norm) should not be an excuse in this age of mass literacy.
Notwithstanding, errors are rife. For instance, in the American media it is common to hear the erroneous phrase “under someone’s watch” for the normative “on someone’s watch.” Such errors are testimony not only to the difficulty language users encounter in sorting out the variety of prepositional phrase abounding in English but to plain ignorance as to which preposition governs which noun. Sic transit gloria linguae americanae!