Usages of zurück
Er lächelt zurück.
He smiles back.
We could have used our new word hinüber. here:
Er lächelt zu ihr hinüber.
Traurig geht er zurück zur Arbeit.
Being sad he goes back to work.
Here traurig is used as an adverb, but it can be an adjective as well:
Der traurige Mann geht zur Arbeit zurück.
Der traurige Mann geht zur Arbeit zurück.
The sad man goes back to work.
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