Are there other punctuation marks that are also used only in English?
No, in dutch, we say: ” ‘s Avonds ”, wich means ” in the evening ”.
French uses it too for truncation of words.
German uses it as well: Wie Geht’s?
French uses it when vowel meets vowel; l’addition (f); l’amour (m). C’est (Ce est) moi. Elle m’(me) aime.
I just remembered that the Donizetti Opera, Elixir of Love, translates into L’elisir D’amore. So, Italian, I guess, does the same as French when vowel meets vowel, but I am guessing.
Hawaiian does too-so guess your theory’s moot
Gotta love fluther. Just saying.