At the same time as aspirates became voiceless spirants, voiceless stops appearing before dental aspirates became voiceless spirants (SD/419). The primitive combinations influenced in this way were ✶[ptʰ] and ✶[ktʰ], which became [fθ] and [xθ], respectively. Presumably, since Tolkien did not mention any changes, the voiceless stops remained in the combinations ✶[tpʰ], ✶[kpʰ], ✶[pkʰ] and ✶[tkʰ], becoming [tf], [kf], [px] and [tx].