I know we can use both fruit and fruits (countable noun and uncountable noun):
The fruit began to rot.
The fruits began to rot.
What has confused me is passion fruit because it has the word fruit in it! Is passion fruit a noun, or is it an adjective (passion) and a noun (fruit)? I assume the former but I am not sure because of the singular/plural forms of mouse/mice (in regards to the animal and computer equipment — same word, but different meanings). This is why I am questioning my own ears when I say the following out loud:
There are many passion fruit in this bowl.
There are many passion fruits in this bowl.
I have read Is using "fruits" as the plural of "fruit" acceptable? which is nearly a dupe other than it doesn’t specifically state by region, and although fruit is used as an example I’m not sure if it applies as I’m talking about a different noun.
So my two questions are
- Are all four examples acceptable in English?
- Are all four examples acceptable in American English?