Help! This is getting tedious. I finished my tree a while back and my lessons were golden for many months. Then Duolingo changed. My lessons including the basics are red, blue, purple and green. 15 lessons of the basics are so monotous.
C'est une torture. Je ne suis pas calme!
That's a beginning and is true as far as it goes. However it's much broader because its not just people (girls and boys), it applies to almost every thing (ie all nouns, adjectives and adverbs). We refer to the concept as masculine and feminine. So "la" is for feminine nouns, pronouns, etc. and "le' is for masculine nouns and pronouns. Its way beyond just people.