Using Basecamp in other languages
Basecamp's interface is in English only. That said, all text fields — project names, to-do lists, messages, tool names, and more — support any language, so your team can write and work in whatever language you use.
Customizing tool names
If you'd like the built-in tool names (like "Message Board" or "To-dos") to appear in your language, you can rename them inside each project. Click the ··· menu at the top right of the project, choose Customize project tools, rename the tools, and save.