Questions & Answers about C'est ma chanson préférée.
The lesson is about c'est with invariable adjectives, so why does préférée have a feminine 'e' here?
In general statements like 'Music is great' (La musique, c'est génial), the adjective directly following c'est is always masculine singular. However, in this sentence, c'est is followed by a noun phrase (ma chanson). The adjective préférée belongs to the noun chanson, so it must agree with that feminine noun.
Since chanson is feminine ('song'), why do we use C'est instead of Elle est?
Why does préférée come after the noun rather than before it?
Most French adjectives follow the noun they describe. The exceptions are usually short, common adjectives describing Beauty, Age, Goodness, or Size (the BAGS rule). Since préférée does not fit those categories and is derived from a verb participle, it follows the standard rule and goes right after the noun.