"I am eating my sandwich."
Translation:Je mange mon sandwich.
Can someone explain what is the difference between "mon" and "ma", I wrote Je mange ma sandwich, and it was wrong.
"Mon" and "ma" both meant "my," but mon is used for masculine nouns: mon sandwich, mon stylo, mon sac, etc. Ma is used with feminine nouns like: ma lettre, ma maison, ma voiture. Unlike English, the agreement comes with the noun not the person possessing it. Therefore it is always masculine even if a woman owns the sandwich. Her sandwich = son sandwich.
Check out the tips and notes here: https://www.duolingo.com/skill/fr/Possessives/tips-and-notes