Hypothetical condition clauses in the past tense are parts of a complex sentence that allow you to play with thoughts and ideas. What would have happened had the circumstances been different? In these complex sentences, both the independent and subordinate clauses are in the subjunctive II form. The subordinate clause expresses the circumstance or condition. It is introduced by "wenn" or "falls" and a comma separates it from the superordinate clause. The superordinate clause describes the potential outcome. In past-tense hypothetical condition constructions, the subordinate clause is always in the past tense. But the main clause, which conveys the potential outcome, can refer to the past, present or future.

Examples:
Wenn wir dich nicht getroffen hätten, hätten wir die Suche wahrscheinlich gestoppt. (main clause: past)
Wenn wir dich nicht getroffen hätten, hätten wir jetzt keine Hoffnung mehr. (main clause: present)