连词与副词有何区别?

只有连接词（连词）才能连接句子（除了句子,它们还能连接单词和短语）.
比如,
--My brother and I went shopping yesterday.(连接单词brother以及I)
--Working hard and playing happily are both important to me.(连接短语working hard以及playing happily)
--I'm seventy years old but I have a young heart.(but 连接两个句子)
副词在句子里仅仅修饰动词、形容词、其他副词以及全句.
--He walked quicky towards her.(quickly修饰动词walk)
--He is very handsome.（very修饰形容词handsome）
--He speaks En glish very well.(副词very修饰副词well)
--He sang the song whole-heartedly.（whole-heartedly修饰全句