多年来老师们都以为他是个笨蛋。用英语怎么说？

多年来老师们都以为他是个笨蛋。

For years, teachers had figured him for a dullard.

for

prep. 为，为了，倾向于，关于，当作；conj. 因为，由于；

例句
I've come looking for a bit of advice.
我特来讨教。

years

n. 年( year的名词复数 )，年纪，一年的期间，某年级的学生；

例句
His wife was sentenced to seven years imprisonment for aiding and abetting him...
他的妻子作为他的从犯被判入狱7年。

teachers

n. 教师( teacher的名词复数 )，师资；

例句
The book is an invaluable aid to teachers of literature...
这本书对于教授文学的老师来说帮助非常大。

had

v. 有（ have的过去式和过去分词 ），（亲属关系中）接受，拿，买到；

例句
He claimed that his parents had abandoned him...
他声称父母遗弃了他。

figured

adj. 以图形和数字表示的，华丽的；

例句
He figured out that you're lonely, like most widows, and he turned on the charm.
他看出你和大多数寡妇一样很寂寞，所以就拿出他的魅力来了。

him

pron. (he的宾格)他；

例句
They said goodbye to him as he got aboard the train at Union Station.
当他在联合火车站登上火车之际，他们向他道别。

dullard

n. 愚人，笨蛋；