2b) Bill worked hard so that he was promoted
İn this sentence, "he was promoted" is the result. İt definitely happened (no doubt)
But when it comes to this sentence:
1b) Bill worked hard so that he would be promoted.
it is an intended future purpose.
It makes me feel that, it is an intended future purpose but we are not sure if the promotion occured or not.
Am I right? or İs it certain that the promotion occured as in the sentence 2b too?
My confusion is about conjuction type of "so" which refers to result of main clause
Bill worked hard so he was promoted .
("Bill was promoted" is the result of "Bill worked hard")
I have usually seen this type as "so" alone in the sentence without "that"
Can I make this sentence with "so that" in the same meaning with the sentence in which "so" is used alone. (that is, the result meaning, not the future purpose meaning)?
Bill worked hard so (that) he was promoted.
İs "that" optional in result meaning of "so"?