When is "Lui" used as the subject? I'm learning French without paying much attention to the rules of grammar, but sometimes a point of grammar catches my attention. This is one. I believe that it would be correct, when speaking of one person, to say: Il va visiter la France, and if I'm speaking of two people, it becomes: Ils vont visiter la France, but if identify the two people separately, it becomes: Lui et son ami vont visiter la France. Since the same person is still the subject, why is it not: Il et son ami vont visiter la France. Why does the pronoun change from "Il" to "Lui" in this context, and are there other situations where something similar happens?