Conceding a Point with “shì”

这本书是有意思，可是太难了。

Zhè běn shū shì yǒu yìsi, kěshì tài nán le.

This book is interesting, but it is too difficult.

他是很努力，不过方法不太对。

Tā shì hěn nǔlì, búguò fāngfǎ bù tài duì.

He is indeed hardworking, but his method is not quite right.

东西是便宜，质量却不太好。

Dōngxi shì piányi, zhìliàng què bù tài hǎo.

The thing is cheap, but the quality is not very good.