mistake

and no mistake

(informal)without any doubt

(非正式)无疑地，确确实实地

it's a bad business and no mistake.

毫无疑问，这一情况很不妙。

by mistake

accidentally; in error

意外地；错误地

she'd left her purse at home by mistake.

她意外把钱包留在家里了。

make no mistake about it

(informal)do not be deceived into thinking otherwise

(非正式)不用有任何疑问，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）不可能被认错