Breakdown of Haben sie mal über die Affäre diskutiert?
haben
to have
sie
they
über
about (a topic)
diskutieren
to discuss
Questions & Answers about Haben sie mal über die Affäre diskutiert?
What does mal do in this question?
Here, mal acts as a conversational flavor word (a modal particle). It softens the question and translates best to "ever" in English. It makes "Did they discuss the affair?" sound more casual, like "Did they ever happen to discuss the affair?"
Why is the past participle diskutiert and not gediskutiert?
Verbs that end in -ieren (like diskutieren, studieren, or passieren) do not take the ge- prefix when forming the past participle. They just drop the -en and add a -t ending.
Why is there an über in this sentence?
In English you just discuss something, but in German you usually discuss about something. The verb diskutieren is typically paired with the preposition über, followed by the accusative case (which is why we use die Affäre).
How can you tell if sie means "they", "she", or the formal "you"?
The verb tells us it is plural: we use Haben instead of Hat, so it cannot mean "she". We also know it is not the formal "you" because sie is written with a lowercase letter in the middle of the sentence. Therefore, it has to mean "they".