Which sentence contains an error in its second-conditional structure?
If I spoke Japanese, I would guide the exchange students.
If the orchestra rehearsed locally, more young musicians would attend.
If our garden had deeper soil, these roses would thrive.
If the orchestra would perform locally, more young musicians would attend.✓Correct answer
Explanation
The orchestra sentence is erroneous because would perform appears inside the if-clause. A past form such as performed is required there, while would belongs in the result clause.