A language may be conservative in one respect while simultaneously innovative in another. Bulgarian and Macedonian, closely related Slavic languages, are innovative in the grammar of their nouns, having dropped nearly all vestiges of the complex Slavic case system; at the same time, they are highly conservative in their verbal system, which has been greatly simplified in most other Slavic languages.[9] English, which is one of the more innovative Germanic languages in most respects (vocabulary, inflection, vowel phonology, syntax), is nevertheless conservative in its consonant phonology, retaining sounds such as (most notably) /θ/ and /ð/ (th), which remain only in English, Icelandic and Scots.[10]