Cariad Cywir
Cariad Cywir, or Troi'r wythnos yn flwyddyn, is a Welsh folk song that focuses on somebody experiencing unrequited love, as s/he sings, "Trio'r wythnos yn flwyddyn, troi'r flwyddyn yn dair
Rwy'n ffaelu troi 'nghariad i siarad un gair (Turn the week to a year, turn the year into three
I can't turn my true love to speak to me)". But s/he swears that "as long as the sea is salty still", s/he will still love him/her.

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Lyrics

Welsh folk songs
Year of song unknown
Songwriter unknown