Comment by hipnoizz

'grzmot' has just one syllable, right (https://en.wiktionary.org/wiki/grzmot). So yes, you can't stress the penultimate one, as it isn't there. ;-)

I think 'Jóźwiak' would be syllabified as 'Jóź-wiak' or 'Jó-źwiak'. I may be wrong, I think we don't have always just one way to syllabify a word in Poland.