他的肌肉很结实啊！

Tāde jīròu hěn jiēshi a!

His muscles are really solid!

我买了一张结实的椅子。

Wǒ mǎi le yì zhāng jiēshi de yǐzi.

I bought a sturdy chair.

我们需要一条很结实的绳子。

Wǒmen xūyào yì tiáo hěn jiēshi de shéngzi.

We need a very sturdy rope.