不一定

jí shǐ nǐ fēi cháng cōng ming xué yè chéng jì yě bù yī dìng jiù yōu xiù

即使你非常聪明，学业成绩也不一定就优秀。

It doesn't necessarily follow that you're going to do well academically even if you're highly intelligent.

zhè huà fǎn guò lai shuō jiù bù yī dìng duì

这话反过来说就不一定对。

The converse of this statement may not be true.

wǒ bù yī dìng qù zhè yào kàn wǒ lèi bu lèi

我不一定去。这要看我累不累。

I might not go. It depends how tired I am.

gēn tóng líng rén jí péng you zài yī qǐ bù yī dìng néng xiāo chú zhè zhǒng gū dú gǎn

跟同龄人及朋友在一起不一定能消除这种孤独感。

Being with peers and friends does not necessarily solve this feeling of loneliness.