我的經驗都是用詞性去判斷(或乾脆翻譯),像樓上大大說的一樣,關係代名詞後面接的子句會不完整,因為它是個形容詞。
ex.(舉上面大大的例子)
The news (that she talked about) frightens me.
talked about(談論有關)後面受詞應該是the news
完整翻譯應是:她談論的那個消息嚇到我了(應該啦...
如果這句硬是寫成that子句(子句完整,文法語意錯誤)那會變成:
The news (that she talked about the news) frightens me.
翻譯起來就會怪怪的
[那個新聞(她在談論的那個新聞)嚇到我了]