47 Two successive syllables are seldom allowed to begin with a rough mute. Accordingly
- a. In reduplication a rough mute is changed to the smooth.
- b. In the θη-passive the aorist imperative ending -θι is
changed to -τι.
- c. The verb-stems θε- put and θυ- sacrifce become τε- and
τυ- in the θη-passive.
- d. Several stems that originally began with one rough mute
and ended with another have lost the aspiration at the beginning of most forms, but retain the aspiration there whenever
the final mute loses it.