Of all the uncountable nouns this one is one of the hardest.
Chocolate has the following countable forms:
whole (chocolate)
piece
bar
chunk
Cake has the following countable forms:
whole (cake)
slice
piece
So you can say:
I made cakes.
I made chocolates.
She baked ten cakes.
He eat four chocolates.
Bread does not have 'bread' as a countable form. Some countable forms are:
loaf
roll
baguette
bloomer
bap
(there are many)
but 'bread' is not one of them.
You can say: "I baked bread" but you are using it in its uncountable form. If you add a picture, you may get it wrong.
There are some real examples from English language learners:
"I just baked the bread."
Bread is being used in its uncountable form and so you can't use 'the' as the determiner. Correction:
"I just baked this bread"
"I want to make a bread."
Bread is being used in its uncountable form and so you can't use 'a' as the determiner. Correction:
"I want to make bread."
"I'm good at baking cakes and breads. I really like the breads I baked."
This one is a great example. 'Cakes' is correct because there is a countable form called 'cakes'. There is not of countable form called 'bread' so it must have no 's'. The second sentences has a determiner but it is correctly used. Why? The 'the' is referring specifically to the bread that the writer made. It still can not have the 's'. Correction:
"I'm good at baking cakes and bread. I really like the bread I baked."
Here are some sentences with countable forms of bread:
I baked two loaves of brown bread today. They were delicious.
The burger I bought came in the softest bun.
I had two rolls with my soup.
In France they love baguettes.
Can you count 'cake' like 'a cake' and 'two cakes'? In this case, does that mean a whole cake, not a piece? What do 'a slice of cake' and 'a piece of cake' mean exactly? I would like to know the exact concepts of them. How are they different? By the way, why 'police' is a plural? Can you say 'the police' but not 'a police' or 'polices'? Are there any words like 'police'?
Wow! Great questions from @choijinah_. Let's take each one in turn:
Yes, there is a 'whole' form of a cake and so you count them as 'one cake', 'two cakes', 'three cakes'. It does not mean 'a piece' it means the whole cake (uncut).
'Slice of cake' and 'piece of cake' mean almost exactly the same. The only difference I can think of is that if the cake is uncut I would ask for 'a slice' or 'a piece'. If the cake is already cut I would ask for a 'slice'. However, that is only a difference in my usage, not grammatically.
Yes! When you count 'uncountable' nouns you are counting the form of the noun, not the noun itself: