This paper puts forward the argument that the concept of the language of trust and trustworthiness can be a useful way of understanding what trust means in specific situations. This concept refers to linguistic devicesverbal and non-verbalwhich purposefully convey trust and create a foundation for continuing or improving relations. The concept has been developed based on research into relations between premodern merchants and their urban governments. In this context, the language of trust has emerged from historical sources as a tool which was used with great skill. By studying the form, the functions and the content of the language of trust in a concrete setting, contemporary or historical, we can grasp what can constitute the basis for trust and trustworthiness. The second argument proposed here is that, by pointing to the foundations of trust, the language of trust reveals the core values of an individual, a group or a society at a given time and place.