English is more conservative in the phonology of its consonants. English has preserved Proto-Germanic /θ/ and /w/, which have become /d/ and /v/ in German; English has preserved initial /s/+consonant, which became /ʃ/ in German; final consonants in German are devoiced; and then there's the High German Consonant Shift, whereby voiceless stops became fricatives or affricates (/p, t, k/ > /f~pf, s~ts, x/) and voiced stops became voiceless (/b, d, g/ > /p. t, k/) in German, but in English they remained the same.

Nice question, had to think a bit for this one. Also not quite sure about your "conservative" - I have a rough idea, though. ;) 1) The differences among German dialects are greater than those among English ones. Bavarian and Low German differ so much in vocabulary and pronunciation that a speaker of the former may in some cases not understand a speaker of the latter. I find that in the English language the variations among dialects (British, American, Australian, Indian etc.) are less pronounced. In my opinion, this attributes a greater flexibility to German in its adaption by local groups of native speakers. 2) Medical terms. English mostly draws on Latin / Greek in order to label diseases, and if you don't know either language, you have to guess or look up what the doctor said :D. In German, we usually have an equivalent "common sense" name for every "scientific" name, e.g. Pneumonie / Lungenentzündung, Appendizitis / Blinddarmentzündung, Bandscheibenvorfall / "Rücken".

Conservative in what way? Hard to measure this in a language, no?