大意 has two distinct meanings: (1) careless/negligent (adjective), and (2) main idea/gist (noun). Context determines which meaning applies. As 'careless,' it's often used with 太 or 不能.
mistakes
Don't confuse the 'careless' meaning with 大方 (generous) or 粗心 (careless). 粗心 is a personality trait, while 大意 describes a momentary lapse.
