Constants.
As far as I know, the constant pi is never used in the plural form.
Ralph seemed to have more trouble than anyone else he knew. The constant woe in his life was a constant source of pain.
The plural of 'this' is 'these' and the plural of 'that' is 'those'.
Isthmi is plural. There are actually two plural forms. I will list them from singular to plural. Isthmus - Singular Isthmi - Plural Isthmuses - Plural
"eys" like "monkeys" "keys" etc. the only exception is "monies"
The plural of rose is roses. The plural possessive is roses'.
The plural of 'bunch' is bunches.The plural of 'ant' is ants.The plural of 'batch' is batches.The plural of 'day' is days.The plural of 'chimney' is chimneys.The plural of 'tomato' is tomatoes.The plural of 'umbrella' is umbrellas.The plural of 'donkey' is donkeys.The plural of 'sky' is skies.The plural of 'foot' is feet.The plural of 'show' is shows.
The plural form of can is cans.
applied is does not have a plural but is apply it does have a plural.
The plural is a regular plural, attics.
The plural for the noun loss is losses; the plural possessive is losses'.
pluralsThe word plurals is the plural of plural. As in: I answered the question about plurals to the person who didn't know that the plural of plural is plurals.