When a stop (voiced, voiceless or aspirate) appeared after an aspirate [pʰ], [tʰ], [kʰ], the aspiration was transferred to the end, devoicing the following stop in the process. The examples given by Tolkien were the combinations [pʰt], [pʰd], [pʰtʰ] which all became [pʰtʰ] (SD/421).

Tolkien noted that combinations of stops were rare (SD/421), most likely because consonants pairs usually included at least one continuant, as discussed under medial-consonants. The only example he gave of this development was the word sapthân, phonetically [safθān].

Furthermore, he stated that where this development was the result of verbal or noun inflection, the change was often reverted for consistency with other noun or verb forms. The example he gave was the verb *saphad- whose aorist tense would have become saphda > saptha under normal phonetic development, but was reformed back to saphda (SD/421), presumably by comparison to other forms such as the past tense *sapphada.

This change preceded other changes (aspirates to spirants) and was therefore probably early. Note that aspirates in ancient Quenya caused a similar change, except that the preceding aspirate lost its aspiration and became a voiceless stop (PE19/87).