When combined, 儿子 (érzi) creates a clear, unambiguous two-character word for “son.” The two characters, both originally meaning “child/son,” reinforce each other.
The concept of a 儿子 (érzi) carries significant cultural weight in China, far more than “son” typically does in modern Western cultures. Traditionally, sons were vital for 传宗接代 (chuán zōng jiē dài) - carrying on the family line. Because Chinese lineage and inheritance have historically been patrilineal (passed through the father's side), having at least one son was seen as essential to continue the family name and ancestral worship. This connects directly to the core Confucian value of 孝 (xiào), or filial piety. A son was traditionally expected to be 孝顺 (xiàoshùn) - filial and obedient - and bear the primary responsibility for caring for his parents in their old age. While daughters were also expected to be filial, they would typically “marry out” of the family and join their husband's family. Comparison to Western Culture: In most contemporary Western societies, the emphasis on a son carrying on the family name is much weaker. Surnames are often seen as a simple identifier rather than a sacred lineage. The responsibility for elder care, while still a family value, is more often viewed as a shared duty among all children, regardless of gender, and reliance on social security or nursing homes is more common and less stigmatized. The now-phased-out One-Child Policy (1979-2015) intensified this cultural pressure. A family with a “single son” (独生子, dúshēngzǐ) would place all their hopes, dreams, and future security on him, creating a unique social dynamic for an entire generation.
In modern China, 儿子 (érzi) is the standard, everyday word for “son.” It is used in all situations, from casual conversation to formal documents.