What is the plural possessive of glass?

Answer 1

The noun glass has a number of uses, all of them are uncountable nouns, except for a drinking glass. The plural possessive is glasses'; the set of glasses' color.

The singular possessive for a pair of glassesused for eyesight is glasses', the glasses' frame. The plural possessive is the glasses' frames. The plural possessive is the same because it is a shortened form for the pairs of glasses' frames.

The singular possessive for a pane of glass, used for windows is the glass's size. The plural possessive is the glass's sizes. The plural possessive is the same because it is a shortened form for the panes of glass's size.

Answer 2

The noun 'glasses' as a word for eyewear, is a plural, uncountable noun; a short form for a pair of glasses or pairs of glasses.

The singular and plural possessive is glasses'.

Examples:

I can't find my glasses' case.

I made all of my glasses' cases myself.

The possessive form of the noun 'glasses' as the plural form of drinking glass is also glasses'.

Example: The wine glasses' pattern matches my china.

Answer 3

The correct form would be "glasses'."