When you create a notebook, you have to define a recognition language.
To do so, tap Manage Languages to see the list of available languages, then tap the black arrow symbol to download the language you need.
The process is similar on Android, iOS and Windows.
Note: Once a recognition language is set for a notebook, it cannot be changed later on. However, since English is very popular, it is recognized in any case and in addition to any language you define.
Updates of Nebo recognition languages are regularly available:
To get the latest resources, tap the + icon to create a new notebook and tap Manage Languages then tap the Update button as shown below.