"After the lunch we are playing."
Translation:Na de lunch spelen we.
That's not true. "Na the lunch" is a prepositional phrase, it's not a conjunction. There is no subordinate clause here.
Instead, the verb and the subject have switched places because in Dutch the verb is always the second element of the sentence (or rather, of the main clause). This is known as inversion. Because "na de lunch" was moved to the beginning of the sentence for emphasis, "we" must come after the verb "spelen".
See here for more about inversion: https://www.duolingo.com/comment/3733010
And more about prepositional phrases: http://en.wikipedia.org/wiki/Adpositional_phrase#Prepositional_phrases
Why not "We spelen na de middageten"? EDIT: I just realized middageten is a "het" noun. Is that the reason? If so, could one say "We spelen na het middageten"?
It would be a correct sentence in Dutch, just none one accepted for the exercise, as I assume they want us to use the "the verb is always in the second place" rule.
Why is aan het needed here? Wouldnt Na de lunch wij zijn spelen be correct?