Hi I have a question about the usage of un de/l'un de.. For example: Je suis allé chez un de mes amis, ou Je suis allé chez l'un de mes amis. Are both of these correct, and if so, is it merely a question formal vs. informal speaking? I swear I have seen/heard examples of both, and I'm wondering if there's something I'm not picking up in the context or if it's really just the author's/speaker's choice, as is the case with on vs l'on. Thanks much. Moderator note: multiple threads merged to create this one.