One of the key features of English is that it has a clear distinction between main and subordinate structures. And there can only be one main clause in a sentence, or one main verb in a clause. (Liu, 2012)
•However, the distinction is not clearly encoded in Chinese. In a topic chain or serial verb construction, it may not be clear which is main and which is subordinate structurally. (Liu,2012)
刘美君 . 英文文法有道理！重新认识英文文法概念 . 台湾：联经出版社 , 2012.