We probably pretty much know what 'slow down' and 'speed up' means, but what if we switch the last speed words from those 2 first speed words, but in same position to as:
'slow up' and 'speed down'
Then will these 2 re-formed speed words that I just put there would make any since?
If these 2 does, then what would these two re-formed words would mean in new speed definition form?