关于三个个单词的辨析（请加上例句说明）

often 经常
always 总是
usually 通常
这三个是表示频率的

次数最多，最常做的是用always 再来是 usually 最后是often

例句：
How often does he go swimming?
1)Always.He goes swimming every day.
2)Usually.He goes swimming third times a week.
3)Often.He goes swimming once a week.