I would like to know the origin/reason of the final t in the German word Werft, as I read that in old German it was just Werf - and in other Germanic languages that t does not appear either (e.g. English wharf).
Thanks in advance.
Unetymological dental stop suffixes are not infrequent in ModHG, e.g., jemand, Obst and Axt. Sometimes they have no apparent meaning but the common theme is generally to add weight or emphasis to the word. This is to some extend still productive. E.g., there is an emphatic affirmative answer Eben! in German (much like Exactly! in English) and some people jokingly pronounce it Ebend! if they want it to sound even more emphatic and even though it is not an established variant it never fails to be understood this way by native listeners.
Very interesting. Concerning the word Obst, I had always thought (mistakingly?) of the -st ending as a sort of superlative - was ganz oben (auf den Bäumen) steht - in a sequence ob(en)-ober(comparative)-obst… , and had never thought of a -t suffix.
This is not uncommon in English too. We have Sir Jimmy Young's “Orft we jolly well go” as well as "yerst" for yes, and I knew a Yorkshire builder who consistently said and wrote "troughting" for troughing. So it seems to be idiosyncratic and related to the morphology of the vocal organs, not etymological. Is it perhaps comparable to "chimbley" for chimney, or to the interpolated -t- in French constructions like a-t-il, to ease the tongue around certain vowel structures?
Be careful with French words or English words from French. An unexpected final -t in nouns or adjectives are mostly residues of Old French case endings. This applies to your example tyrant and alemant > allemand. The -t in ancient is best explained by contamination from French loans in -ent.
Examples where one might recognise an analogy to the German emphatic -t/-d are -t suffixed to adverbial -s like in again>againes>againest>against or while>whiles>whilest>whilst.
I had a Hungarian friend with the unusual-looking surname Ongjerth.
It turned out to be a Transylvanian Saxon name, derived from "Ongjer", which is apparently a dialectal pronunciation of "Ungar" (meaning "Hungarian"), plus an unetymological "t" ending.