How to say"我已经欣赏了他的七部作品"in English?

work 作品(侧重写作方面)
opus 著作(艺术作品,乐曲)

appreciate 欣赏(持赞赏态度)
enjoy 欣赏(侧重享受着)

I have alreadly appreciate/enjoy seven works/opera of his.
（注：opus是可数名词，复数形式属于不规则变化，为opera。）

我已经欣赏了他的七部作品
I've already appreciated seven works of him

I have already appreciated seven worka of his.
当作为具体工作和具体艺术作品时可数,him-his,指的是他所有作品中的7部

I have already appreciated his seven works.

I've already read 7 pieces of his works.
欣赏最好不用APPECIATE，一听就是CHINGLISH

一楼的，work是不可数名词。。
I have already appreciated seven work of him.