1、often后接动词原形用于一般现在时；2、often后接动词过去式用于一般过去时。
we often例句
We often plan our meals well in advance
我们经常很早就计划好要吃什么。
We often slept under the stars.
我们经常在夜空下露宿。
We often underestimate our potentialities.
我们常常低估自己的潜力。
We often alert the public to the need for pollution control.
我们经常提醒公众注意控制污染的必要性。
