了解频率表达在英语中的重要性，我们来看看以下词汇及其用法。
首先，"always"代表持续不断，"usually"表示常态，"often"意味着频繁，"sometimes"则表示偶尔，而"hardly ever"和"never"则表示几乎不或从未。这些副词用于描述动作的频率，通常在一般现在时中使用。例如：
I always have some milk for breakfast.
Usually, he gets up at 6:30 in the morning.
He often does homework before dinner.
Sometimes he goes to movies on Friday evenings.
I hardly ever eat out at noon.
I never arrive late for school.
区分"How often"和"How long"的用法也相当关键。当我们想知道某人做某事的频率时，用"How often"提问，如：
How often do you watch TV?
回答可以是：Every day, Once a week, Three times a week, Often.
相反，如果想了解持续的时间长度，用"How long"，如：
How long do you usually watch TV?
回答可以是：About one hour, Three hours, Thirty minutes.
此外，关于次数的表达，英语中通常用基数词加"times"来表示，如"once, twice, three times"等，基数词后直接跟times来明确次数。这就是频率表达的基本概念。