Rule for feminine · die
-in (feminine professions) → die · 1.4%
The suffix -in turns a masculine profession or nationality noun into its feminine form, and the result is always die: Schauspielerin (actress), Sängerin (singer, f.), Präsidentin (president, f.). The rule is very solid when -in is truly an added suffix (Schauspieler + in, Sänger + in), but not every word that happens to end in -in follows the feminine gender - our set has 13 such exceptions, including Verein (club/association), Termin (appointment), Stein (stone), Wein (wine) or Magazin (magazine), all masculine or neuter. So always check whether -in is added to a recognizable base word, not just whether it appears at the end.