The phrase literally translates to “speaking words (说话) that don't count as words (不算话).” The first “话” is the action of speaking, while the second “话” is the substance of the promise. The phrase elegantly captures the idea that the promises spoken have become meaningless and void.
In Chinese culture, one's word is deeply connected to their personal honor, integrity, and social standing, a concept encapsulated by 信 (xìn - trustworthiness). The traditional saying “言必信，行必果 (yán bì xìn, xíng bì guǒ)“—meaning “one's words must be trustworthy, and one's actions must be decisive”—is a cornerstone of personal virtue. Therefore, accusing someone of being “说话不算话” is more than just calling them “flaky,” as one might in Western culture. While “flaky” often implies forgetfulness or poor time management, “说话不算话” is a direct challenge to a person's character. It suggests they are fundamentally unreliable and lack integrity, which can cause them to lose face (丢面子 - diū miànzi) and damage relationships (关系 - guānxi) significantly. In business and personal life, being known as someone who is “说话不算话” can lead to social and professional isolation.
This phrase is almost always used in a negative and critical context. It's an accusation or a complaint. You can use it in various situations, from casual friendships to serious business negotiations.