The plural of material is materials.
The word means is plural. This word can be used while being a plural word. For example, the doctor would write a prescription if it means the patient will get better.
The plural form of "Chinese" is "Chinese." The word stays the same in both the singular and plural forms.
The word material is a noun. The plural noun is materials.
The word 'dates' is already plural. The singular form is just 'date'.
Roofs is already a plural noun. The singular form is roof.
Baggage is already plural.
The plural form of the word "physics" is still "physics" as it is already a plural noun.
The plural form for the noun 'material' is materials.
the word dozen is already plural.
The word "executives" is already plural.
The plural of diary is diaries.
The word 'attorneys' is already plural !
bosses is already plural from the word "boss"
Nevi is the already plural word of nevus.
*legislation the word "legislation" is already plural.
Rushes is already a plural. The singular is rush.
The word doctorates already is plural. The singular form is doctorate.