to look up the correct name
There are two kinds of alveolar fricatives in English: voiceless /þ/ as in thin and voiced /ð/ as in that. The name of the first character is thorn and that of the second one is edh. Voicing is a rather common distinctive feature in many languages. The stops /p/, /t/, and /k/ are voiceless, and /b/, /d/, and /g/ are their voiced counterparts. Usual the term hard is used to distinguish fricatives or affricates from stops: e.g., the g in gel from that in goat.
Many languages borrow words with no intention of paying back the loan. It's one of the ways that languages get new vocabulary.
