For example: X will not occur until Y [STRIKE]have[/STRIKE] has occurred.
Does this mean X will occur after Y or does it mean X and Y will occur at the same time.
First of all, I am very thankful for your wonderful explanation because now I understand what the phrase [STRIKE]meant[/STRIKE] means.
Also, I should have mentioned that my English is quite horrible so please bear with me.
You've answered my question completely and now I can mark this thread as solved.