usually often sometimes always 是分为哪一类的?

usually often sometimes always 是分为哪一类的? 频度副词always/usually/often/sometimes/never的用法区别 频度副词always.usually.often.sometimes.never的用法区别 always,usually,often,sometimes用法的区别?急!@ always、usually、often、sometimes放在句子的哪里? always,usually.often.sometimes,seldom,分别是什么意思 sometimes always often usually哪一个用于现在完成时 sometimes often usually always never 造句 用always often sometimes never usually usually often occasionally sometimes的频率区别是怎样的 用always,usually,often,sometimes,hardly ever,never写一片短文,是英语对话 频度副词（always,usually,often,sometimes,never）后面跟的动词是什么形式的?