usuallyoften属于什么词性often后面加todo还是do

usuallyoften属于什么词性？

usuallyoften属于副词词性

例句

1.

Third, over 6/ 10 of the teachers investigated say they usually or often request their students to read textbook before ( or after) lessons and to be active in classroom, while the students read less than they were expected.

超越6/10的被调查教师总是或常常要求学生在课前（或课后）阅读考试教材、在课堂上进行活动，而学生的对应回答比教师的回答要低得多。

2.

Specialized platforms are usually simpler and often provide some unique services.

针对平台一般比较简单，经常提供某些独特的服务。

属于副词，在句中做状语，经常会用到大多数情况下目前时。usually"经常，一般"，often常常。比如:I often read English in the morning.我常常早晨读英语。

usually 一般

often 常常

这俩都是副词，大多数情况下目前时的标志词。

often后面加todo还是do？

I often +动词原形。我常常做某事。

　 I often go swimming.我常常去游泳。　 I often read English books.我常常读英语书。

　 I often eat with a knife and fork.我常常用刀叉吃饭。

其他表示频率的副词：always, sometimes, never.

I always ride my bike to school. 我总是骑我的自行车去学校。

Sometimes, I write stories in English. 有的时候我用英语写故事。

I sometimes clean the blackboard for my teacher.我有的时候，为我的老师擦黑板。

I never go by bus.我从不乘公共汽车去。 I never play with dolls.我从不玩玩具娃娃。