we could not believe what he did to us
correct
The map showed where the party would be held
correct
We never know whether we will get paid or not
correct
The instructor explained where was the computer lab located
Incorrect; no subject after connector "where"
can you tell me why was the mail not delivered today?
incorrect; the position of second subject and verb
The manager explained how wanted the work done
Incorrect; no subject after connector
She told me when should pick her up
Incorrect; no subject after connector
It is unfortunate that the meal is not ready yet
Correct
Do you want to know if it going to rain tomorrow?
incorrect; no second verb
This evening you can decide what do you want to do
Incorrect; the position of the second subject and verb