The word perfume can be a group noun if referring to the industry, or to scented materials as a whole. But having more than one perfume would have the normal form "perfumes", e.g. She purchased various perfumes.
There is no plural form for the word, countries. This word itself is a plural.
The plural form for the demonstrative pronoun this is these.
The plural form of the word "inferno" is "infernos."
There is no plural word for if.
The plural form is data.
The plural form of the word "baby" is "babies."
The plural form of vow is vows.
The plural form of the word "pharynx" is "pharynges."
The plural form for the word 'pioneer' is pioneers.
In Chinese, the plural form of the word "minute" is "分钟" (fēnzhōng).
The plural form for the noun valley is valleys.
The plural of diary is diaries.