/'ɒfn, also 'ɒftən; [US] 'ɔ:fn; `ɔfən/
adv
1 many times; at short intervals; frequently 常常; 经常; 时常
*We often go there. 我们常去那儿.
* We have often been there. 我们常在那里.
* We've been there quite often. 我们经常在那里.
* It very often rains here in April. 这儿四月份常下雨.
* He writes to me often. 他经常给我写信.
* How often (ie At what intervals) do the buses run? 公共汽车隔多长时间一班?
2 in many instances 在很多情况下
*These types of dog often have eye problems. 这种狗的眼睛很多都有毛病.
* Old houses are often damp. 旧房大都潮湿.
3 (idm 习语) as often as each time that; as many times as 每次; 每当
*As often as I tried to phone him the line was engaged. 每次我给他打电话都占线. as ,often as `not; more ,often than `not very frequently 往往; 大抵
*When it's foggy the trains are late more often than not. 雾大时火车往往误点. ,every so `often occasionally; from time to time 偶尔; 有时; 不时. once too often => once.

adv
[Date: 1200-1300; Origin: oft]
if something happens often, it happens regularly or many times
= frequently
　She often works at the weekend.
　If you wash your hair too often, it can get too dry.
　How often do you see your parents?
quite/very often
　I quite often go to Paris on business.
　Robin is a difficult child; you've said so yourself often enough (=a lot of times) .
it is not often (that)
　It's not often that a government minister will admit to being wrong.
if something happens often, it happens in many situations or cases
　It's often difficult to translate poetry.
very/quite often
　Very often children who behave badly at school have problems at home.
all too oftenalsoonly too often
used to say that something sad, disappointing, or annoying happens too much
　All too often doctors are too busy to explain the treatment to their patients.
　This type of accident happens only too often.
every so often
sometimes
　An inspector comes round every so often to check the safety equipment.
as often as notalsomore often than not
spoken usually
　More often than not the train is late.