When learning the French subjunctive, there are lists of verbs and expressions that are helpful when deciding if you need to use it or not. However, that’s not all you need to know about the subjunctive. Sometimes using it is situational, and it depends on how sure you are about the statement you’re making.
👉 Subjunctive: Assumptions / Judgements
👉 Indicative: Facts / Reality
The following adjectives require the subjunctive when you’re not absolutely sure that what you are saying is a fact.

👉 Subjunctive: C’est le dernier livre qu’il ait Ă©crit.
👉 This is the last book that he wrote. (that I’m aware of)
👉 Indicative: C’est le dernier livre que j’ai lu.
👉 This is the last book that I read. (I know this for a fact)
Use the indicative when stating the first or last time something happened.

Superlatives
Superlatives work the same way as the adjectives listed above. Everything depends on whether something is known as a fact or if an assumption is being made.

👉 Subjunctive: Ce sont les enfants les plus bruyants que je connaisse.
👉 These are the noisiest children (that) I know. (Assumption – Maybe I have met noisier children at some point in my life)
👉 Indicative: Ce sont les enfants les plus bruyants que j’ai gardĂ©s cet Ă©tĂ©.
👉 These are the noisiest children that I have looked after this summer. (Fact – I looked after five, and these two are the noisiest)
RELATED POSTS:
👉 French Subjunctive – How to form and when to use it
👉 French Subjunctive or Indicative Expressions List
👉 French Verb Falloir – How to avoid using the subjunctive