be under no illusion

US /biːt əˈraʊnd ðə bʊʃ/
UK /biːt əˈraʊnd ðə bʊʃ/
"be under no illusion" picture
1.

不抱幻想, 清醒地認識到

to understand the true facts of a situation and not have false ideas

:
You should be under no illusion about the difficulty of this task.
你對這項任務的難度應該不抱任何幻想
We are under no illusion that this will be easy.
我們不抱任何幻想認為這會很容易。