In the sentence 'I put the book on the desk.' why is 'on the desk' considered an adverbial of place rather than an object complement?

I want to talk to lonely people

I want to be teacher

Can I ask "Do you go to your dance class on Monday?" or is "Do you go to your dance class on Mondays?" the only correct way? Also if the first one would be correct, could it mean Monday as every Monday, or would it imply just a really casual way of using present simple to talk about one particular day ?

Pronunciation Poll

it is probably a mistake to credit dolphins with any motive of life-saving. What does ‘with’ mean in this sentence ？