父(ちち) chichiが ga亡(な)く()な()っ()て() nakunatteから kara３ 3年(ねん) nenになります ninarimasu。 It's been three years since my father passed away. Literal Father [subject-が] passed-away [since-てから] 3-years [into-に] becomes [polite-ます]. ~てから + [time]になる is a set pattern for expressing elapsed time since an event: 'it has been X since Y.' Polite and natural. deathfamily~てから (after doing)
父(ちち) chichiが ga亡(な)く()な()っ()て() nakunatteから kara３ 3年(ねん) nenになります ninarimasu。 It's been three years since my father passed away. Literal Father [subject-が] passed-away [since-てから] 3-years [into-に] becomes [polite-ます]. ~てから + [time]になる is a set pattern for expressing elapsed time since an event: 'it has been X since Y.' Polite and natural. deathfamily~てから (after doing)