I am bad at explaining the difference between PT and OT.

I am bad at explaining the difference between PT and OT. 

Also, had hairsplitting disagreement with mom about the difference between a goal and an aim (in context). I think aim implies that something can be missed, i.e., failed, in fact, you could keep aiming all day and never get anywhere near it. Whereas, while people can fail to achieve a goal in reality, the word does not already imply the possibility, so suggests a broader potential to be reached.