I know these sentences work:
We don't know where to put the sofa. (where we should put the sofa)
No one could tell me how to start the engine. (how I should start the engine)
The rules didn't specify who to speak to in case of an emergency. (who you should speak to)
I had no idea what to write my home paper about. (what I should write my home paper about)
But are the followings do, too?
Search for "[yourcity] department of sanitation". They are who to call when there is a dead dog in the road.
Wow so if you need to know anything about the city of Helsinki, what district is good for what, where you can get the best food, the most fun bars – all that – then the staff at The Yard are who to ask.
What I would like to know is whether this pattern serves as a complement, aside from serving as an object in the first four examples.
Thank you very much.