How to use correctly use 是否? I'm not entirely sure what is suppose to follow 是否. For example, I'd like to say:


  I wasn't know (or wasn't sure) if you heard me clearly.


I'm not sure if this is how it should be translated:


  我没确定你是否听清楚出我刚说的话


I'm also curious if this is correct:


  我没确定你是否听到了我。


How should the above be properly translated? And, more importantly, how do I use 是否 in general?
是否 roughly maps to whether in a yes-no interrogative sentence or clause.
For your sentence, you should use 不知道 or 不确定 instead of 没确定. 没确定 means haven't confirmed yet. Also 听得清 (could hear) is more polite than 听清了 (have heard). If the context allows, it is more natural to omit 我说的话.

I wasn't sure if you could hear me clearly.
我不确定你是否听得清(我说的话)。

General usage of 是否 is pretty straight-forward. You can check out Iciba for examples.