3B1 Expresses doubt around the occasion, without a doubt expects it not to happen. 3B2 expresses uncertainty, it'd or may not happen. 3B3 expects that it will happen. Stack Exchange network consists of 183 Q&A communities which includes Stack Overflow, the most important, most trusted online Local community for builders https://share.evernote.com/note/ef30f82f-3303-2f87-d3ae-55e1a8797749