I know there's also a 'ne' littéraire where you can indicate negation while dropping 'pas'. This applies exclusively for a short list of verbs, like pouvoir.
If I were to see a sentence like "J'ai peur qu'il ne puisse le faire", would the 'ne' here be a 'ne' expletif or a 'ne' littéraire? In other words, am I afraid that he can do it or that he cannot do it?