"Our father lets us swim in the sea."
Translation:Unser Vater erlaubt uns, im Meer zu schwimmen.
December 30, 2012
It represents a change of subject, or the fact that the subject is missing from the second clause. The actor of "swimming" is "us", not "our father." Check out infinitive clauses: http://www.mein-deutschbuch.de/lernen.php?menu_id=49#infinitiv_mit_zu