说一不二

zài zhè jiàn shì shang wǒ shuō yī bù èr

在这件事上我说一不二。

I mean what I say on this matter.

tā shuō yī bù èr dā ying de shì yī dìng néng bàn dào

她说一不二，答应的事一定能办到。

She is a man of his word, and never makes a promise she can't keep.

yī gè shuō yī bù èr de rén

一个说一不二的人

a person who stands by their word

tā shì shuō yī bù èr de méi rén néng fǎn duì

她是说一不二的，没人能反对。

She is a man of her word, and no people can disagree her.