dupre wrote:
Can you tell me what "invariable" means when talking about a Spanish adjective?
That's when it's irrespective to gender.
Feliz, caliente, confiable, suave, veraz, dulce, elegante, verde... (happy, hot, trustable, soft, truthful, sweet, elegant, green).
Variable adjectives depend on gender:
Enojado (a), frío (a), duro (a), seguro (a), cansado (a), hambriento (a), rojo (a) ... (angry, cold, hard, sure, tired, hungry, red).