Where does “sommigen” come from?

sommigen (Dutch) comes from Dutch sommige, from Middle Dutch sommich, from Middle Dutch som, from Old Dutch sum, from Proto-West Germanic *sum, from Proto-Germanic sumaz, from Proto-Indo-European sem- — together, one.

Ancestry of “sommigen”, step by step

StepLanguageWordMeaning
1Dutchsommigesome
2Middle Dutchsommich—
3Middle Dutchsomsome
4Old Dutchsumany, some
5Proto-West Germanic*sumsome
6Proto-Germanicsumazsome (one), a certain (one)
7Proto-Indo-Europeansem-together, one
Every word from Proto-Indo-European sem- →Every word from Proto-Germanic sumaz →Every word from Proto-West Germanic *sum →