繁體字的英文是什麼？簡體字的英文是什麼？

If you refer to the entire set of language, then:
traditional Chinese
simplified Chinese

If you refer to the individual "words", then:
traditional Chinese characters
simplified Chinese characters
(not "writings" ar!!!)

繁體中文字是 traditional Chinese (writing)
簡體中文字是 simplified Chinese (writing)

writing是書寫的意思,如不需要的情形下, 可以省掉。

繁體字:the original complex form of a simplified Chinese character

簡體字: the simplified (Chinese) character

繁體字 Traditional character
簡體字 Simplified character

我推薦您一個非常不錯的英語學習網站，里面有很多非常不錯的學習資源：

http://www.hkenglishstudy.info

希望可以幫到你!