hin or chin?

[Galin]

Originally Posted by Vaine

Only when 'ch' is at the end of a word I recon.

I would say Beregond's quote refers to all positions in Sindarin.

Also, JRRT notes that Rohan and Rohirrim represent Gondorian pronunciation. In Sindarin proper the words are Rochan(d) and Rochirrim for example (S. roch 'horse'). Gondorians weakened this sound to h in certain circumstances (as noted in Appendix E) and some altered word final ch to k (as noted in Unfinished Tales).

Some Gondorians said Rohan for S. Rochan and Ork for S. Orch.