Which full report correctly uses statement order in the reported-yes-no-question contrast? Direct after departure: "Did the passengers board at Gate 4?"
The dispatcher asked whether the passengers had boarded at Gate 4.✓Bonne réponse
The dispatcher asked whether did the passengers board at Gate 4.
The dispatcher asked if had the passengers boarded at Gate 4.
The dispatcher asked whether the passengers did boarded at Gate 4.
Explication
Whether the passengers had boarded places the subject before its auxiliary and clearly locates boarding before the later enquiry. Whether did the passengers board and if had the passengers boarded both retain direct-question order.