江 (jiāng) vs. 河 (hé): For learners, a crucial distinction is between `江` and `河 (hé)`. While both mean “river,” there's a strong geographical and historical convention. `江` is almost always used for major rivers in southern and central China (e.g.,
长江 Cháng Jiāng,
珠江 Zhū Jiāng). `河` is typically used for rivers in northern China (e.g.,
黄河 Huáng Hé). Using “珠河” would sound very strange to a native speaker.