He was rebellious from a very young age, always questioning rules.

rebellious 是形容词，由名词 rebel（反叛者）加上形容词后缀 -ious 构成。rebel 来自拉丁语 rebellis，意为"再次发动战争"，引申为"反抗、反叛"。 rebellious 形容人"叛逆的、反抗的"，指不愿服从权威或遵守规则的性格特征。