How to pronounce “connecting word” in English

"or not" can be placed into the sentence, you don't have to write it and you don't have to say it.But when you can place it in there that means the connecting word you need is "whether." So "We need to know whether 'or not' we're going to proceed with this project." Not "if.""If" sets up a condition. "If we proceed with this project we're gonna need more money." In other words, upon a certain condition "we're gonna need more money." So that distinction