Every language has speech styles, some typical labels for which are ‘neutral, ‘formal’, ‘colloquial’, etc. Part of one’s ability to speak (and write) correctly is the knowledge of what speech style is appropriate in what context in a given language. While norms of linguistic appropriateness may vary considerably across languages, there is no language in which a knowledge of these norms is absent in a non-pathological speaker’s command of the language.
The pathological misuse of stylistic norms in speech was demonstrated yesterday in Donald Trump’s widely broadcast comments on the suicide bombing in Manchester (England). Trump called the bomber an “evil loser.” In the sense meant by Trump, Merriam-Webster Unabridged defines ‘loser’ as “one who is incompetent or unable to succeed.” Stylistically, especially in American English, this word has a colloquial or informal connotation, which makes it fundamentally incompatible with the adjective ‘evil’ used and meant in its strict (non-figurative) sense.
To call a suicide bomber, who killed and maimed innocent children (among his victims in Manchester yesterday), a “loser” is a pathological use of the colloquial style in American English because it makes what can only be considered a terrible murderer into someone who is merely a misfit or (incorrectly, given the attack’s success) a failure. Trump’s linguistic choice of words in this instance is––tragically––of a piece with his other pathologies.