Det är svårt att förklara med ditt exempel, eftersom man normalt skulle formulera den meningen annorlunda: "I USA har det uppstått en diskussion..." Jag tar därför ett annat exempel: - USA har diskuterat frågan. (aktiv form) - Frågan har diskuterats av USA. (passiv form)

http://blog.lardigsvenska.com/2013/02/from-aktiv-form-till-passiv-form.html https://blogs.transparent.com/swedish/making-active-verbs-passive-in-swedish/ https://en.wikipedia.org/wiki/Swedish_grammar#Passive_voice Obs: I konstruktionen med "vara", som i din andra mening, används perfekt particip (gripen osv.) i stället för supinum (gripit).

In the sentance in question the tense changes from Supinum(Supine) to Perfekt-Particip(Participle), a more formal case. Since Gripit is a pretty abstract word to beguin with i'm having a hard time finding examples that, by law, aren't Particip. -Polisen har gripit brottslingen Taken from Wikipedia: "In Old English, past participles of Germanic strong verbs were marked with a ge- prefix, as are most strong and weak past participles in Dutch and German today," "Past participles, or participial phrases (clauses) formed from them, are used as follows: -The chicken has eaten (Perfekt) -The chicken was eaten -The chicken, who was eaten by -Eaten in this manner; -With the chicken eaten;