what is the difference between
much fruit and many fruits?

‘Fruit’ can be countable or uncountable, but the countable form refers to different kinds of fruit only. As such, these sentences are correct:

(Speaking of a nearly empty basket of bananas) There isn’t much fruit in this basket.
(Speaking of a nearly empty basket of bananas, grapes and lemons) There isn’t much fruit in this basket.
(Speaking of a full basket of lemons and grapefruit) There aren’t many fruits in this basket.


Well , in my opinion “fruit” is a countable noun , so we say " many fruits " and not “much fruit .Fruit can be used without article in genralisation for example"Fruit gives us a lot of energy” but when we specify “which fruit” we’ve to use the article us in"The fruit I bought it yesterday is so delecious"we can also use the preposition “some” ,as an exemple “Some fruit is so expensive”.

I wish Ithe idea have been given.

Well, you have just contradicted yourself. ‘Some fruit is’ is an uncountable example.

Yes , but when we talk about fruit , we 're able to count it and here the problem .

many thanks

No problem. Please read my first post.

Ok , no problem and thanks a lot.

I woild like toknow the difference between: air conditioning and air conditioner. Thanks!

The first is the system; the second is the machine.

ok but which is the most correct":
switch on the air conditioner?
switch on the air conditioning?

install the air conditioner or
install the air conditioning?

Both of the first pair sound reasonable, but use only the first member of the second pair.