A typeface needs to support the actual language of the content. Accented letters, punctuation and different character shapes can reveal problems that a sample headline hides. I check these details early, before a font becomes central to the visual identity.
The test should include headings, body copy and small interface labels. If a fallback appears unexpectedly, spacing and tone can change within a single word. Language support is part of selecting a reliable type system, alongside its visual character.