I was under the misapprehension that the course was for complete beginners.

我误以为这门课是给纯粹的初学者开的。

《牛津词典》

Men still appear to be labouring under the misapprehension that women want hairy, muscular men.

男人们似乎仍误以为女人喜欢体毛多的肌肉男。

《柯林斯英汉双解大词典》

Non-disease exists when a patient is under the misapprehension that disease is present.

非疾之病之存在，乃是病人误认它的存在。

youdao

Many are under the misapprehension that it is a vote to authorise new spending, not permission to pay the bills that this and earlier Congresses have already run up.

ECONOMIST: Lexington

Neither you, nor anyone else having an interest in this case, should be under any misapprehension about the effect of the punishment part of a life sentence.

BBC: NEWS | UK | Scotland | Glasgow and West | Lord Menzies sentence statement