1、含义不同loud和loudly只指“大声地,高声地”;而aloud除指“大声地”外,还可指“出声地”。The hungry baby cried aloud.饿了的婴孩哭得很大声。He has a loud voice.他的嗓门很大。He wept loudly.他大声哭泣。2、搭配不同aloud作“出声地”解时,主要与read, think等连用‘作“大声地”解时,主要与call, shout, cry等连用;loud与talk, speak, sing, laugh等连用。loudly可与任何发出声响的动词(如:bring, explode, knock,ring, insist, demand, explain等)连用。He read her letter aloud to the rest of the family.他把她的信大声读给家人听。I heard a loud bang and then saw black smoke.我听到砰的一声巨响,接着就看到了黑烟。3、词汇位置不同loud和aloud只能用在动词后面,loudly则既可用在动词后,也可用在动词前。She spoke very loudly.她说话的声音很大。I heard a loud crash in the kitchen.我听到厨房有一声巨响。The little boy is crying aloud.那个小男孩哭的很厉害。4、侧重不同loud侧重状态和给人的感觉,loudly则侧重方式。比较级或最高级时,通常用 loud,而不用 loudly。Who laughed loudest? 谁笑的声音最大?He read his sister"s letter aloud. 他喃喃地读他妹妹的信。Suddenly the bell on the wall rang loudly. 突然,墙上的铃大声地响起来。