a specific use of the subjunctive

Question

Hello,I would like to know a specific rule regarding the use of the subjunctive.I learned that the subjunctive is not used in a sentence where the same subject appears in both the main and subordinate clauses.But when I came across this sentence, I got lost.“Non, je ne pense pas que je sois trop jeune !”I've searched everywhere for the reason why the subjunctive is used. In vain.However, I can't help but assume that the main clause is negative, so the subjunctive should be used for the subordinate clause.So, I'd like to enrich myself with a correct information, please.Thank you in advance for your help.

Jim Jones · Accepted Answer

Bonjour Umi O,
When the verb penser is used in a negative sense, then the following clause needs to be in the subjunctive mood because doubt is being expressed.
"I do /did not think ....."
Can someone please explain the Subjunctive to me!
https://french.kwiziq.com/revision/grammar/expressing-the-most-least-that-i-have-ever-with-a-superlative-followed-by-the-subjunctive-mood-in-french-le-subjonctif
https://www.lawlessfrench.com/grammar/subjunctive/
Bonne journée
Jim

Umi Oshimaski · Answer

Bonjour Jim J.,Thank you very much for your response!And yes, I was aware of it thanks to the fantastic lessons at Lawless French’s site!However, when we have the same subject both in the main and the dependent clause, “the rule is we don’t use the subjective.”The site says: 2) Two subjectsThe subject of the main clause and that of the dependent clause must be different. If they’re the same, just use the infinitive. Je veux que j’aille à la banque.This made me confused!Because this phrase is not negative.So… whenever we have the negative main clause, even though the same subject is used, we must use the subjunctive! Correct? For example, “Il ne crois pas qu’il puisse aller à Tokyo la semaine prochaine.”There are so many things to learn! And I love it!Thank you again! Excellente journée!

Maarten Kamp · Answer

Umi,

To your further query after Jim’s response about conveying an element of doubt with the subjunctive.

This is a stylistic choice - there is a non-subjunctive alternative here ‘ je ne pense pas être trop jeune ‘ .

However, sometimes in French by way of ‘ formality ‘, or ‘ it just sounds better ‘ or basic ‘ feel ‘ for the language and its minor nuances such as emphasising an element of doubt, a native speaker will choose to use the subjunctive trigger clause when an alternative structure exists.

In this case ‘ ne pense pas que …. ‘ is the trigger clause, and when used obligatory trigger clauses will (mostly) be followed by the subjunctive, regardless of the fact that there is no subject change.

The linked discussion on stack exchange may be of interest to you :

https://french.stackexchange.com/questions/39733/subjunctive-mood-when-the-the-subject-is-the-same-in-main-and-dependent-clauses

https://www.lawlessfrench.com/subjunctivisor/penser/