When the object is definite, such an object is, more often than not, moved to the beginning of the sentence (O + S + V) or moved before the verb (S + O + V).
O + S + V and S + O + V are regarded by some as topic–comment structures.
这本书， 我 看过了。 这本书， 我看过了。
Zhè běn shū，wǒ kàn guò le。 Zhè běn shū，wǒ kàn guò le。
O S V
Pre-posed object Topic Comment
I have read this book.
 Yip, P. C., Rimmington, D., Xiaoming, Z., & Henson, R. (2009). Basic Chinese: a grammar and workbook. Taylor & Francis.
 Teng, W. H. (2016). Yufa! A practical guide to Mandarin Chinese grammar. Taylor & Francis.