I’m using this code:
echo sprintf( _n( '%1$s / %2$s', ' %1$s every %2$s', 3, 'my-domain' ), 99, "3 months" );
The output is ’99 every 3 months’.
But I’ve .mo/.po files translating the string: %1$s every %2$s
Into another language: %1$s ogni %2$s
Why the translated string isn’t used by _n ?
The WordPress Codex says:
the parameters $single, $plural, and $number will first be passed to
the domain’s ngettext() method.