What is the plural for weiss?

Answer 1

Names that end in "s," "x," "z," "ch," and "sh," are appended with 'es' to become plural:

• The Joneses invited you to hold ladders while they hang lights.
• The Foxes decorated four Christmas trees.
• The Alvarezes went to visit their grandmother.
• The Churches sang in the top-hat choir.
• The Ashes got stuck at the train station.

Never use an apostrophe to make a name plural. Apostrophes are for possessives.

• The Joneses' dinner was a success.
• The Foxes' house was beautiful.
• The Alvarezes' grandmother was delighted.
• The Churches' singing was heavenly.
• The Ashes' train derailed in the mountains.