"I can go with him?"
Translation:Je peux aller avec lui ?
Maybe because of this grammar rule: http://french.about.com/library/pronunciation/bl-contractions.htm - "Exception: When the first person singular subject pronoun je is inverted, it does not contract." Examples cited are Puis-je + avoir, and Dois-je + être.
Pronouns are 'stressed' when they are after prepositions.
I wrote simply, "Je puis aller avec lui?" because I thought that "puis" and "peux" were interchangeable. Eons ago when I first studied French, they were, and I just did it on the spur of the moment. Is "puis" never used anymore? It was rejected by DuoLingo and I see it discussed here only in the context of "puis-je".