Affinity Publisher uses the Hunspell Engine for spell checking and it also allows for additional Hunspell dictionaries to be added. You can download additional dictionaries from here. To use them in Affinity Publisher, please follow the below instructions: Please note: There are some differences between how you install Hunspell dictionaries for macOS/Windows, since we use the default spelling dictionaries available within macOS but it's also possible to add custom Hunspell dictionaries too.