Mixed mutation in Sindarin
This mutation is never explicitly referred to in any published material, we don’t even know what it’s called, mixed mutation is a term made up by fans. Because it sometimes resembles soft- and sometimes nasal mutation. What we know of it we only know by observing its effects. It occurs after ‘e’/‘en’ and after prepositions incorporating -in:
e, en (=of the)
erin (=on the)
ben (=according to the)
nan (=to the)
uin (=from the, of the)
‘nin (=to the, for the)
The mutation table:
You may have noticed that in some cases the words are the same in their mutated form. As example I have used ‘cost’ and ‘gost’, these both become ‘e-gost’, for their meaning we must rely on contextual clues.
Ps. I just noticed, with a few words I have included an example with ‘erin’ as well as ‘en’. All of these words can of course also be mutated with ‘erin’ in front. That I have only included examples with a few words does not mean it’s not possible with all other words as well.