often不是情态动词。情态动词后面要接动词原形。情态动词有:can may must should could 等。often是个频度副词，和一般现在时态连用，通常表示经常发生的动作。often的位置：表示“经常”，通常放在行为动词之前，特殊动词（助动词、情态动词以及动词be）之后。
often的用法
often的用法：一般用于动词之前, be 和助动词之后, 有时也用于句末以加强语气。
1.often放在be动词后。
He is often late for school.
他经常上学迟到。
2.often放在实义动词前。
He often goes to school by bike.
他常骑自行车上学。
3.often与very或quite连用表示强调时，既可放句中，也可放句首或句末。
My father very often goes to Beijing on business.
Very often my father goes to Beijing on business.
My father goes to Beijing on business very often.
我父亲经常去北京出差。
often的短语
every so often
有时,偶尔 sometime
Every so often, she takes a weekend in London.她有时在伦敦过周末。
as often as not
1.经常;在通常情况下
其实我有两个家，因为我常去她家里。
I had two homes really, because as often as not I was down at herhouse.
more often than not
1.往往，多半
食物很少，他们经常挨饿。
food is scarce and more often than not they go hungry.
