At this point and time, it's pretty clear that the words "awful" and "awesome" aren't interchangeable. But why do their prefixes sound identical?
Our listener Kalen asks: “Why is ‘awesome’ a positive word and ‘awful’ a negative word?”
This is a great example of how two words can start in the same place and end up with quite different meanings.
Since both of these words meant “awe-inspiring” at one point in their lives, we should look at “awe” first.
“Awe” has changed meaning over time, which helps explain why “awful” and “awesome” have changed over time. Early on, “awe” meant fear or dread. Therefore, to be “awe-inspiring” meant to inspire awe or dread.
However, later on “awe” comes to mean respectful fear or reverence – for example, someone could be in awe of the dead. This shift affects “awesome” and “awful.”