"Good advice" or "A good advice"
On Duolingo, I saw this sentence for translate to English:

"Ese es un buen consejo".

I wrote:

"That is a good advice".

But that is incorrect, because the correct form is "That is good advice".

Why "good advice" and not "a good advice"?

Sorry for my bad English.

Question

"Good advice" or "A good advice"
On Duolingo, I saw this sentence for translate to English:

"Ese es un buen consejo".

I wrote:

"That is a good advice".

But that is incorrect, because the correct form is "That is good advice".

Why "good advice" and not "a good advice"?

Sorry for my bad English.

Answer

Because in English "advice" is uncountable, so you can't put "a" before.

Answer

The word "advice" is an uncountable noun. Uncountable nouns do not have plural forms. They cannot be used with the articles a/an.
You can use "some" before "advice":
He gave me some advice. 
To refer to a single item of advice, you can use the expression ‘a piece of advice’:
Can I give you a piece of advice?

Answer

Advice is an uncountable noun.

advice | AmE ədˈvaɪs, BrE ədˈvʌɪs |
noun
1 uncountable(counsel) consejos mpl; (professional) asesoramiento m
▸ a piece of advice
un consejo

Answer

You can say "he gave me ten pieces of advice about girls" if you want to specify the number of tips. And don´t forget the 3rd person S: "That meanS": :)

Answer

Ok. That mean I can't say "He gave me ten advices about girls", for example?