2. The absence of affricates (аффрикаты) and sibilants (свистящие, шипящие).
3. Dependence of the quality of the consonants on the environment (окружение) in the word:
a) phonemes, denoted by the letters f, þ (ð), s could be voiced or voiceless. They were voiced in the intervocal position. This position could be made up of a vowel and a voiced consonant.
CONSONANTS
hlāf, oft [f] – hlaford, lifde [v]
tōþ [θ] – tōþes [ð]
ʒōs [s] – ʒōses [z]
But doubled consonants were always voicelss: offrian [f:] (предлагать), sceþþan[θ:] (вредить), cyssan [s:] (целовать).