Orthography
Old Swedish used some letters that are no longer found in modern Swedish: ⟨æ⟩ and ⟨ø⟩ were used for modern ⟨ä⟩ and ⟨ö⟩ respectively, and ⟨þ⟩ could stand for both /ð/ (th as in the) and /θ/ (th as in thing). In the latter part of the 14th century ⟨þ⟩ was replaced with ⟨th⟩ and ⟨dh⟩.
The grapheme ⟨i⟩ could stand for both the phonemes /i/ and /j/ (e.g. siäl (soul), själ in modern Swedish). The graphemes ⟨u⟩, ⟨v⟩, and ⟨w⟩ were used interchangeably with the phonemes /v/ and /u/ (e.g. vtan (without), utan in modern Swedish), and ⟨w⟩ could also sometimes stand for the consonant-vowel combinations /vu/ and /uv/: dwa (duva or dove).
Certain abbreviations were used in writing, such as ⟨mꝫ⟩ for medh (modern med, with). The letter combinations ⟨aa⟩ and ⟨oe⟩ were often written so that one of the letters stood above the other as a smaller letter, which led to the development of the modern letters ⟨å⟩, ⟨ä⟩, and ⟨ö⟩.
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