and no mistake

(informal)without any doubt

(非正式)無疑地，確確實實地

it's a bad business and no mistake.

毫無疑問，這一情況很不妙。

by mistake

accidentally; in error

意外地；錯誤地

she'd left her purse at home by mistake.

她意外把錢包留在家里了。

make no mistake about it

(informal)do not be deceived into thinking otherwise

(非正式)不用有任何疑問，完全可以肯定

there is no mistaking someone or something

it is impossible not to recognize someone or something

（人或物）不可能被認錯