经典必背】
A little body often harbors a great soul. 浓缩的都是精品。
【课文原句】
Betty and I may not get to see each other often, but we will always be best friends. 贝蒂和我可能不会经常见面，但我们将永远是最好的朋友。
I often doubt whether it is worth working so hard. 我经常怀疑是否值得这么努力地工作。
And how often do they have ball games? 他们多久进行一次球类比赛？
【基础知识】
1. often作为频率副词，常放在系动词、助动词、实义动词之前或非谓语动词之后。但sometimes可以放在句首也可以放在句末。
We don't often go to the movie. 我不常去看电影。
Sometimes we go to the movie. 有时我们去看电影。
2. hardly和never本身含有否定意义，句中出现这两个词时，句子的谓语动词用肯定形式。由hardly和never构成的反意疑问句，其疑问部分用肯定形式。
However. I hardly have any spare time for my hobbies such as playing volleyball and ping-pang. 然而，我几乎没有空闲时间来培养我的业余爱好，比如打排球和乒乓球。
Robots never go wrong. 机器人从来不出错。
You never feel bored or unhappy when he is with you, do you? 他和你待在一起的时候，你从来感觉不到乏味或者不开心，是吗？
3. 频率副词根据其表示的频率由高到低依次是：
always→usually→often→sometimes→hardly ever→never
4. 对于由how often引导的疑问句，用表示频率的短语来回答，常放句尾。如：every day; once a week; three times a day; once a month; five times a year等等。
— How often do you watch TV？你多久看一次电视？
— I watch TV every day. 我每天都看。
— How often does your mother go shopping? 你妈妈多久购一次物？
— Nearly once half a month. 差不多半个月一次。
5. how often用来对频率提问；how many用来对可数名词的数量提问；how much用来对不可数名词的数量提问；how long用来问事物的尺寸、长短；how old用来问人或物的年龄；how far用来问两地间的距离；how soon多久以后，多用于将来时。