"We will leave when you have used the bathroom."
Translation:mamej puchpa' Dalo'pu'DI'.
puchpa' Dalo'pu'DI', mamej is grammatically fine.
The course is a little inconsistent about word order in sentences with two clauses such as this one -- some sentences are more lenient about the order of the two sentence parts in Klingon and some just use the same order as the English.
This one is one of those sentences that only accepts versions that have the same order in both languages -- puchpa' Dalo'pu'DI', mamej would then correspond to "When you have used the toilet, we will leave" with the English sentence parts in the other order as well.
I'm not sure which approach (requiring the same order or allowing both) is most beneficial to learners.
Sometimes Klingon requires a specific clause order where English is agnostic about order; in those cases it makes sense to allow the English to go in either order while the Klingon must go in a certain order.
Other times English and Klingon allow clause order to vary in the same way. This sentence is one of those times. In these cases it needs to be decided whether the course allows the same flexibility as the one-sided inflexible versions above. I personally feel that clauses should be allowed in either order going in either direction. It's close enough. It's also what I've encountered doing the Spanish course.
This is not the case. In Klingon, dependent clauses (with verbs ending in -chugh, -DI', -mo', -vIS, or -pa') may be placed on either side of the main clause.
mamej puchpa' Dalo'pu'DI'
puchpa' Dalo'pu'DI' mamej
We will leave when you have used the bathroom.
When you have used the bathroom, we will leave.
Both are correct and more or less interchangeable.