Breakdown of Wir sprachen mit unseren neuen Kandidaten über die Verwaltung.
wir
we
neu
new
sprechen
to speak
unser
our
Questions & Answers about Wir sprachen mit unseren neuen Kandidaten über die Verwaltung.
If we report this past-tense event (e.g., 'They said that they spoke...'), do we need the Konjunktiv II replacement rule taught in this lesson?
No. To report a past event, you use the Konjunktiv I in the perfect tense (a conjugated form of haben or sein + past participle). The form for sie would be sie hätten gesprochen. Because hätten is clearly distinguishable from the regular indicative haben, there is no ambiguity, and the replacement rule (Ersatzform) isn't needed here.
What if the original sentence was in the present tense (Wir sprechen...) and we wanted to report it? Would the replacement rule apply then?
Yes! The Konjunktiv I present tense for sie (they) is sprechen. Because this looks exactly like the normal present indicative, it fails to signal reported speech. To fix this ambiguity, you must apply the Ersatzform and use the Konjunktiv II: Sie sagten, sie sprächen mit unseren neuen Kandidaten... (or würden... sprechen).
Is Kandidaten just a standard plural here, or does it follow a specific noun rule?
Kandidat is an n-declension (or weak) masculine noun. These nouns add an -n or -en to the end in every case except the nominative singular. Since it is plural here (and in the dative case because of the preposition mit), it requires the -en ending to become Kandidaten.
Why does the two-way preposition über take the accusative (die Verwaltung) here instead of the dative?