Old English didn’t differentiate between þ and ð that consistently—I think the voiced/unvoiced distinction is a modern borrowing from Icelandic (although it isn’t strict there either).
Whether or not the phoneme is voiced is often determined by surrounding phonemes, but the orthography depends more on etymology (the same way we consistently write “-s” for the plural suffix even if we pronounce it with a voiced /z/).
Not consistently—the more usual pattern is to use þ at the beginning of words and ð internally, even if the internal sound is voiceless.
In both languages, the two sounds are usually allophones and are perceived as the same sound influenced by context—the way the “th” sound in “breath” and “breathe” are perceived as the same consonant, just influenced by the preceding vowel. (If we wrote “breþ” and ‘breeð”, the different letters would hide the fact that we hear them as the same sound.)
I had assumed they were allophones and always wondered if there was a minimal pair to prove otherwise. It turns out though there is one: tooth (n) vs tooth (v), or tooþ vs tooð.
Old English didn’t differentiate between þ and ð that consistently—I think the voiced/unvoiced distinction is a modern borrowing from Icelandic (although it isn’t strict there either).
Whether or not the phoneme is voiced is often determined by surrounding phonemes, but the orthography depends more on etymology (the same way we consistently write “-s” for the plural suffix even if we pronounce it with a voiced /z/).
Isn’t þ in Icelandic generally voiceless, as in ‘thin’ for example?
Not consistently—the more usual pattern is to use þ at the beginning of words and ð internally, even if the internal sound is voiceless.
In both languages, the two sounds are usually allophones and are perceived as the same sound influenced by context—the way the “th” sound in “breath” and “breathe” are perceived as the same consonant, just influenced by the preceding vowel. (If we wrote “breþ” and ‘breeð”, the different letters would hide the fact that we hear them as the same sound.)
I had assumed they were allophones and always wondered if there was a minimal pair to prove otherwise. It turns out though there is one: tooth (n) vs tooth (v), or tooþ vs tooð.