Use 'inane' when critiquing something that lacks depth or thoughtfulness, especially in casual talk. Their inane banter didn't contribute to the discussion at all.
Pro Tip 2/3
Informal Contexts
'Inane' fits better in informal settings; using it in formal writings or speeches might seem out of place. The group's inane jokes made the long drive more bearable.
Pro Tip 3/3
Non-personal Use
Using 'inane' for things, not people, avoids directly calling someone foolish, which can be rude. The movie was filled with inane dialogues.