心底

他tā从cóng心底xīndǐ笑xiào了le出来chūlái。

He laughed a hearty laugh.

我wǒ打dǎ心底xīndǐ里lǐ感激gǎnjī你nǐ。

I thank you from the bottom of my heart.

他tā把bǎ情感qínggǎn藏cáng进jìn了le心底xīndǐ，装出zhuāngchū热心rèxīn的de样子yàngzi。

He hid his emotions and pretended to be enthusiastic.

你nǐ问wèn我wǒ怎么zěnme想xiǎng？……好Hǎo吧ba，那nà我wǒ就jiù把bǎ我wǒ的de心底xīndǐ话说huàshuō出来chūlái吧ba。

What do I think, you say ... well then, I'll give you my candid opinion.