I have a doubt connected with example of one sentence.
When someone comes to a meeting with me and I was not sure of that fact before, should I say:
a) I didn't know if you come.
b) I didn't know if you would come.
b) is OK, or I didn't know (that) you were coming/were going to come.
And one more thing, is there a future tense shift after "whether" as it is after "if".
a) "I am not sure whether he will do it." (do something in the future)
b) a) "I am not sure whether he does it." (do something in the future) ?