It’s an urban myth that the Inuit have 100 different words for “snow”, but there certainly are - quite understandably - lots of words for “hill” and “mountain” in Welsh!
Is there a simple guide to distinguish between types of hill in Welsh? I’m thinking that my university dictionary gives me these words for hill:
twyn, tyle, allt, bre, bryn, gallt, garth, and rhiw. It only gives mynydd for mountain, although I know the Brecon Beacons are “bannau”.
Are the hill words interchangeable, or do they specifically relate to different types/shapes of hills (of course, we have lots of words for hill in English too - tump, mound, hillock, hill, knoll and so on)?