I'd like to make sure if I understand the combination "a piece of fruit" correctly. It can mean either one single apple, orange, banana etc or a slice of an apple, banana etc, can't it?
When I see/hear 'a fruit', I should expect the writer/speaker talk about a kind of fruit, shouldn't I? However, I can't think of any example, let alone a good one. How common is 'a fruit'?
It does. So simple. But "an orange is a kind of fruit' looks safer
I would normally take "a piece of fruit" to be a slice or section or part of a fruit, not to be a whole fruit. So in "he gave them each a piece of fruit", I would expect some to receive a quarter or a half or a slice of apple, some to receive one or more liths/segments of orange, some half a pear, some a slice of watermelon, ....
However I accept that it is possible to use the phrase loosely, and they could have been given an apple, an orange, a pear ... but they would be unlikely, let's face it, to get a whole watermelon. But if he was giving whole fruit, the sentence would probably be "he gave them each a fruit", and 'a piece of' would not appear. Hope this helps.
For me, "a piece of fruit" means a whole apple, a whole banana, etc.
There is a fruit bowl on the buffet line. Everyone can take a sandwhich, some chips, a piece of fruit, and a cookie. -- That does not mean "one slice of apple." It means a whole apple.
If you asked me what I had to eat so far today, I would not say "a fruit." I'd say "All I've had is a piece of fruit -- I'm certainly ready for dinner!"
This could be an American difference.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.
In AusE, a piece of fruit is, as Barb says, a whole fruit. We wouldn't say, "Come and have a fruit."
Unlike Tdol, I have heard it and use it in BrE.
For his school packed lunch, my cousin has two sandwiches, a packet of crisps and a piece of fruit.
There are twelve pieces of fruit in the fruit bowl. When I get home, I only want to find six.
I would use "piece" for a whole fruit when I'm not specifying which type of fruit. When I mean a section of a piece of fruit, I would use the relevant term:
Can I have a slice of apple?
Can I have a couple of segments of your tangerine?
Can I have half a kiwi fruit?
Could you cut my banana into slices please?