Meine Mutter sagt, die Steuer für das Auto sei gestiegen.

My mother says the tax on the car has increased.

Breakdown of Meine Mutter sagt, die Steuer für das Auto sei gestiegen.

• sein: to be
• das Auto: the car
• für: for
• meine: my
• sagen: to say
• die Mutter: the mother
• steigen: to rise
• die Steuer: the tax

Questions & Answers about Meine Mutter sagt, die Steuer für das Auto sei gestiegen.

Why does the sentence use sei gestiegen instead of ist gestiegen?

The form sei gestiegen is the Konjunktiv I (subjunctive I) of the perfect tense in reported speech. It signals that you are relaying what your mother said rather than stating it as a fact yourself. In direct speech you’d say „Die Steuer ist gestiegen.“ In reported speech German prefers Konjunktiv I to mark the source of information.

What exactly is Konjunktiv I and when do I use it?

Konjunktiv I is a mood used primarily for indirect or reported speech. You form it from the infinitive stem of the verb plus specific endings. For sein the present Konjunktiv I form is sei, and you pair it with the past participle for perfect tenses: sei gestiegen. Use Konjunktiv I whenever you want to report someone else’s words without quoting them directly.

Why is there no dass before die Steuer in the subordinate clause?

After verbs like sagen, German allows two types of subordinate clauses: • with dass (e.g. Meine Mutter sagt, dass die Steuer gestiegen ist.)
• without dass, if you use Konjunktiv I (e.g. …, die Steuer sei gestiegen.)
By omitting dass and using Konjunktiv I you keep the sentence more concise and clearly show it’s reported speech.

Why does the verb appear at the very end of the clause?

In German subordinate clauses the finite verb always goes to the end. Here sei (the finite part of the perfect) and gestiegen (the past participle) occupy the last two positions:
…, die Steuer sei gestiegen.

Why is die Steuer in the nominative case?

Within the subordinate clause die Steuer is the subject of gestiegen. Subjects in German are always in the nominative case, so you use die Steuer rather than an accusative or dative form.

Why is für das Auto in the accusative?

The preposition für always takes the accusative case. Whatever follows für must appear in accusative, so das Auto becomes für das Auto.

Why does steigen use sein for the perfect tense instead of haben?

Verbs of motion or change of state (including steigen, “to rise”) form their perfect with sein. That’s why in direct speech you say ist gestiegen, and in Konjunktiv I reported speech you say sei gestiegen.

Could I rephrase the sentence in a less formal way?

Yes. A more colloquial or everyday way would be:
• Meine Mutter sagt, dass die Steuer für das Auto gestiegen ist.
Here you use dass plus the indicative perfect instead of Konjunktiv I. It’s perfectly correct but doesn’t emphasize the reported-speech nuance as strongly.