Sequence of Tenses
The tense of a subordinate clause depends on that of a main clause.
If the tense of both clauses is past, then the tense of the subordinate clause becomes tenseless (= present tense).
an fias im la vort. = I am born when he dies.
an fiasat im la vort. = I was born when he died.
an fiasat xi la vortat. = I was born after ha had died.