a wide natural stream of water flowing between banks into a lake, into another wider stream, or into the sea
"the river was navigable for 50 miles"
And hast thou crost that unknown river, Life's dreary bound?
误 We row a boat in the river.
正 We row a boat on the river.
误 Harbin is by the Songhua River.
正 Harbin is on the Songhua River.
误 There is a bridge on the Huangpu River.
正 There is a bridge over〔across〕 the Huangpu River.