How can I best explain that using "Why there is...?" and "Why you did not...?" is incorrect when asking question. Instead, it should be "Why is there...?" and "Why did you not...?" Thanks!
Why there is a shipment hold on the order? (incorrect)
Why is there a shipment on the order? (correct)
Why you did not process the changes? (incorrect)
Why did you not process the changes? (correct)
Please explain the grammar principle that would support the above sentences or questions. Thanks.
(1) You did not process the changes. (declarative)
(2) Why did you not process the changes? (question)
Because when certain elements like the question word "why" occupy initial position in a clause, it triggers subject-verb inversion and the insertion of the auxiliary verb "did", as you can see in (2).