书上英语说：He was reading my words out loud.为什么不用loudly?speak lou

书上英语说：He was reading my words out loud.为什么不用loudly?speak loudly呢?
有句书上的英语说：He was reading my words out loud.为什么不用loudly?speak loudly呢?She went home sad.和She went home sadly.哪个对的啊?请具体分析啊,还有个wait minents还是wait minent?