This study compares the uses of the acronym wtf (‘what the fuck’) in digitally mediated text-based interactions in three typologically distinct languages: American English (source language), and Finnish and Chilean Spanish (recipient languages). The data consist of tweets extracted from the social media platform X. Interactional Linguistics and Digital Conversation Analysis are employed to examine the functions performed by wtf in different positions in a tweet and interaction. Instances of wtf were annotated to describe its uses in the source language and to compare them with those observed in the recipient languages. The study shows that in all three languages, wtf is used in various tweet-internal and sequential positions. These uses expressed the writer’s disbelief, astonishment, and a problem in acceptance towards prior content. The analysis concludes that the pragmatic functions of wtf in American English undergo a narrowing when it is used in Finnish and Chilean Spanish.