The imperfect subjunctive, for reading
CEFR C1
The passé simple: for reading, not speakingRecognising passé simple forms when reading and knowing which infinitive they belong to…Inversion after a fronted adverbInverting the subject after the adverbs that require it, adding the linking -t- where…Cleft sentences: c'est… qui, ce qui… c'estHighlighting an element with c'est… qui, c'est… que and the ce qui / ce que / ce dont…Connectors for formal argumentUsing the connectors that carry a French argumentative text, and telling them apart from…The impersonal constructions of formal FrenchOpening the sentence with impersonal il and giving each phrase its preposition and mood.Accents and the cedillaPlacing é, è, ê and ç correctly, and knowing that in French an accent changes the sound…The rule, in three lines
A tense nobody speaks, met only in reading: qu'il fût, qu'elle eût. It is built on the passé simple, and the third person singular takes a circumflex. Today the present subjunctive replaces it. You learn to recognise it, not to use it.
The usual slip. Reading qu'il fût as an indicative past and translating it as «was». It is a subjunctive: today it would be qu'il soit.
Why it catches you out. English has almost no subjunctive left, so the category itself is unfamiliar. The good news: you only ever need to READ these forms. Nobody writes them today, so there is nothing here you can get wrong in your own French.