The plural is strata (and the correct singular is stratum, which is rarely used in English).
The plural of stratum is strata.
Stratus is named from the Latin word stratus meaning "spreading out" which describes the characteristics of the cloud. It is related to the word stratum, meaning spread out in a layer, used in geology.
The word crises is a plural word; it is the plural form of the word crisis.
There is no plural word for if.
The plural form for the demonstrative pronoun this is these.
A non-plural word, a word (noun or pronoun) that is not plural is singular, a word for just one.
The plural word of delay is delays.
EMU
the plural word is comedones
No it's a singular word. A plural word would be "have".
Leukocytes is the plural of leukocyte
The plural of "classification" is "classifications."