Adverbials of source can involve direction, so in this subsection we will discuss the two types of adverbials together. Adverbials of source/origin are expressed with the prepositional phrases 由/从+NPloc ‘yóu/cóng + NPloc’ (from…). Adverbials of direction are composed of the phrases 朝/向/往+ NPloc ‘cháo/xiàng/wǎng + NPloc’ (toward…). 沿着‘yánzhe’ (along) expresses movement along a certain route or course. The prepositional phrases of 朝/向/往+ NPloc ‘cháo/xiàng/wǎng (toward, to) + NPloc’ may refer to directional path without specifying position or location, as in:
Huǒchē xiàng běi kāi.
(The train was heading northward.)
Tāmen jiā yuànzide dàmén cháo nán kāi.
(The gate of their yard is towards the south.)
Or it can refer to direction along with a location implied:
2a. 一群男孩子朝/向/往 山下走去。
Yī qún nánháizi cháo/xiàng/wǎng shān xià zǒuqù.
(A group of boys were walking down the hill.)
Húmiàn shàng de fēng bǎ xiǎochuán yīzhí xiàng nán tuī qù
(The wind on the lake continuously pushed the little boat towards the south. )
In (2a, b), the locations can be inferred as ‘on the hill’ and ‘on the lake’, and the direction is ‘down the hill’ and ‘towards the south’ respectively.
 Loar, J. K. (2011). Chinese syntactic grammar: functional and conceptual principles. New York: Peter Lang.