Breakdown of Die Kandidaten behaupteten, sie würden die Steuer senken.
sie
they
werden
will (future auxiliary)
die Steuer
the tax
behaupten
to claim
Questions & Answers about Die Kandidaten behaupteten, sie würden die Steuer senken.
Why does this sentence use würden ... senken instead of the Konjunktiv I for reported speech?
Normally, reported speech uses Konjunktiv I. For the third person plural (sie), the Konjunktiv I form of senken is senken. Because this looks exactly like the normal present tense indicative, we apply the replacement rule (Ersatzform) and switch to Konjunktiv II instead.
Why not just use the actual Konjunktiv II form, senkten?
Because senken is a regular (weak) verb, its Konjunktiv II form (senkten) looks exactly like its simple past tense. Since the goal is to make it clearly recognizable as reported speech and not a past-tense fact, we apply a second replacement rule and use the würde + infinitive form (würden senken).
If I wanted to include the word dass (that), how would the sentence change?
You would say: Die Kandidaten behaupteten, dass sie die Steuer senken würden. When you use dass, the conjugated verb (würden) gets pushed to the very end of the sentence. By dropping dass, as this sentence does, the reported speech clause uses standard main-clause word order.
Does the fact that behaupteten is in the past tense affect the verb form in the reported speech?
No. Unlike English, German does not use backshifting. The verb form in the reported speech clause depends only on the original tense the candidates used when speaking (present or future) and the grammatical replacement rules, not on the tense of the reporting verb.