他在理解问题上显得有些迟钝。

Tā zài lǐjiě wèntí shàng xiǎnde yǒuxiē chídùn.

He seems a bit dull in understanding the problem.

这个学生在课堂上表现出迟钝的状态。

Zhège xuéshēng zài kètáng shàng biǎoxiàn chū chídùn de zhuàngtài.

This student shows a dull state in class.

他的学习进展相对较迟钝一些。

Tā de xuéxí jìnzhǎn xiāngduì jiào chídùn yīxiē.

His learning progress is relatively slow.