相当 + Adjective
相当 (xiāngdāng) means 'quite' or 'considerably' and is used as an adverb to intensify adjectives. It indicates a relatively high degree, stronger than 比较 but not as extreme as 非常. Place it directly before the adjective it modifies.
今天的考试相当难,很多人没考好。
jīntiān de kǎoshì xiāngdāng nán, hěn duō rén méi kǎo hǎo.
Today's exam was quite difficult; many people didn't do well.
她的中文说得相当流利,让我很吃惊。
tā de zhōngwén shuō de xiāngdāng liúlì, ràng wǒ hěn chījīng.
Her Chinese is quite fluent, which really surprised me.
这家餐厅的菜相当好吃,下次还来。
zhè jiā cāntīng de cài xiāngdāng hǎochī, xià cì hái lái.
The food at this restaurant is quite delicious; I'll come again next time.