Please speak a little ____ ,I can't hear clearly.

问题描述:

Please speak a little ____ ,I can't hear clearly.
aloud,louder?
应该用aloud吧,但为什么不能用louder

因为aloud是副词,speak是动词,动词是用副词修饰的,而louder是形容词比较级,是用来修饰be动词的.所以用的是aloud.