Hit ist uf angliškan skrivnas.‘This is written in English.’The name of the language is always in the dative, almost always –an, because most languages are really just a weak feminine adjective omitting the word “language,” though you may find it written out in full as well, e.g. uftiža rasta grējutungiškan ‘in the Valthungian language’.
Though it wasn’t intentional, this is funny to me, because it looks and sounds reminiscent of German auf, which is used for language in the same context (“auf Deutsch”) but has exactly the opposite underlying meaning. So in each of these Germanic languages, a different preposition is used:
English ‘in’ – In French*One could also say im Französischen, but that’s another grammar crumb for someone else’s blog.
German ‘on’ – Auf Französisch*
Valthungian ‘under’ – Uf Frankiškan