The plural form of Hass is Hasses, e.g. All the Hasses were invited to the wedding.
If Gelpi is a surname, then the plural is Gelpis.
The plural of the surname may be Simmons or Simmonses.
The surname Hester has the plural Hesters (two Hesters, or the Hester family).
Winters. Plural of winter is winters. Plural of surname Winters would also Winters. Possessive of winter would be winter's.
You wouldn't add anything to pluralise the surname Muniz, you could just say "The Muniz are coming over"
The plural form of the surname Gillis is Gillises.
My last name is Hass, ive heard middle eastern(usually Hebrew). It is also similar to some German names. Sometimes they mean the same(rabbit) but I've also heard it mean hatred(Hebrew) as well as strife.
The plural of Shastri would be Shastris
If Gelpi is a surname, then the plural is Gelpis.
If Hoix is a surname, then the plural is Hoixes
The plural of the surname may be Simmons or Simmonses.
The plural of the surname Sarli would be Sarlis.
The plural of bràthair (brother) is bràithrean. (This would not be for the surname Brothers.)
A surname cannot be pluralized.
The plural form of the proper noun Justiz is Justizes.
In English, the plural is Mullinaxes Other languages make plurals differently.
The surname Hester has the plural Hesters (two Hesters, or the Hester family).