Thank you for clarifying that it "listened" here is "does really refer to the past." What confused me was that I thought "listened" is a past subjunctive.
Hello, Rasha Assem,
I agree with David. The clues to interpret that the past is real (not unreal or "subjunctive," as you say) in the original sentence are "last week" in the condition and "had" in the result. If "last week," which refers to one particular broadcast of the program, and "had," which refers to one specific occurrence in the past (the fact that the program left many questions about trees unanswered) were not present, then we could interpret the condition as describing a habitual situation, and the unreal past interpretation would be possible, for example:
- If you listened to Natural World, you would know many interesting things about the environment. (The person is not a regular listener and as a result ignores many things about the environment.)
Just as I said in this other thread about "would have + past participle" not expressing probability in the present, I wouldn't choose "would" with a simple infinitive to express that meaning either. I would use must or will:
- If you listened to last week’s Natural World, you must / will know that we had a lot of unanswered questions about trees. (The person did listen to that program, so the speaker guesses the person is aware that many questions about trees were not answered.)