Je ne le crois pas

Question

There is a quiz question to translate 'I don't believe so'. The 'so' threw me off.Apparently, the right answer is 'Je ne le crois pas.' It links to this lesson, the neuter 'le'. I am wondering why the 'le' is a neuter pronoun and not a direct object pronoun? Is it because the way croire is used here is actually 'croire que'? Second, when I checked the answer on AI (sorry), it tells me that 'I don't believe that' translates to 'je n'y crois pas'; and 'I don't believe so' is just 'je ne crois pas'. It seems to think that 'je ne le crois pas' can only mean 'I don't believe him' -- as in, 'le' must be a direct object pronoun.
Is any of the AI answer correct, or is it all rubbish? Je ne sais pas si je dois y croire!

Céline Pickard · Accepted Answer

Bonjour Isabelle,
Indeed, "le" is a neuter pronoun because it refers to an entire idea/proposition. Here, you should think about what "so" can refer to. It most likely would refer to a situation or a statement that was just mentioned rather than a thing or a person (in which case, "le" would be a direct object pronoun). And your instinct about "croire que" is correct because the full sentence would be:

Je ne crois pas que ce soit le cas = I don't believe it to be the case
Je ne crois pas que ce soit cela = I don't believe it to be that

-> in both cases, you would replace the subordinate clause "que ..." with the neuter pronoun: 
Je ne le crois pas
 
Therefore, contrary to what the AI told you, "je ne le crois pas" does not only mean "I don't believe him", it can also mean "I don't believe so".
I hope this is helpful.
Bonne journée !