The trustworthy development and use of AI is no longer optional - it is now in fact mandated by governments around the world, including in the US and the UK. But what does it mean to ‘trust AI’ - and how do we build systems that are worthy of our trust? In this talk I will go back to basics and unpack the sociological concept of trust. On the basis of an understanding of trust as a precondition for action I then present case studies of AI adoption. Our studies of contact-tracing apps and robotic disinfection during the pandemic in the UK, and the discourse on social media surrounding the launch of ChatGPT highlight the contextual role trust plays in the (non-) adoption of AI. I will close with some considerations on the design of trustworthy systems.