In a topic-comment sentence, the usual word order is rearranged a bit in order to emphasize a certain part of a sentence. The part that is to be emphasized becomes the topic, and moves to the beginning of the sentence, with the comment on the topic coming after the topic has been stated.

Examples

Zhè tái diànshì , jià ɡé bú tài ɡuì.
这 台 电视 ,价格 不太 贵。
"this television" the topic that is emphasized.The price of this television isn't too expensive.