Swedish nickname
In a sense, all names are two syllables (this is more or less a fact around the world) - one syllable names get lengthened, longer ones get shortened. John > Johnny, Elizabeth > Lizzie. (There are exceptions of course, such as Liz, Beth and so on.) This is done in a few different ways in Sweden depending on which generation you belong to, but a common “traditional” one is to shorten the first syllable and add an -e suffix to a male name: Tobias > Tobbe Karl > Kalle Jan > Janne Fredrik > Fredde Nicklas > Nicke Filip > Fille and so on Jonas > Jonne, but more commonly Jon t e, which also works for John, Johan and Johannes (actually three variations of the same name). There’s a variation to this theme where the phonetics don’t match up: Gustav > Gurra Bertil > Berra Female nicknames work somewhat similarly, mostly with an -i or -a ending instead: Susanne > Sussi Cecilia > Cissi Maria > Mia Karin > Kajsa (not quite sure how that works , actually)...