To clarify: I am not a native English speaker and I hadn't thought about the words themselves before seeing that quote. In German, there is no clear distinction like that. Of course, I also need my solitude.
Dutch also has "eenzaam" (lonely) en "alleen" (single, singular), but neither really confer the same meaning as "solitude". The closest expression in Dutch is probably "op zichzelf", but that still describes a fact, while solitude (feels to me like it) expresses an emotion.
