Where does “sommich” come from?

sommich (Middle Dutch) comes 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 “sommich”, step by step

Step	Language	Word	Meaning
1	Middle Dutch	som	some
2	Old Dutch	sum	any, some
3	Proto-West Germanic	*sum	some
4	Proto-Germanic	sumaz	some (one), a certain (one)
5	Proto-Indo-European	sem-	together, one

Words derived from “sommich”

sommige
sommige
sommigen

Every word from Proto-Indo-European sem- →Every word from Proto-Germanic sumaz →Every word from Proto-West Germanic *sum →