Advice is known as an uncountable known and as such cannot take a plural, because uncountable nouns are considered to be grammatically singular. This advice is good. [not these advices are good]. If you need to make a plural, then you have to resort to the expression 'piece of' [and other similar expressions]. Let me give you one piece of advice. Let me give you some advice. Let me give you two pieces of advice. This piece of advice is good. These two pieces of advice are good. Similar to advice are the following words: information, meat, luggage, furniture, rubbish, baggage, equipment. Instead of 'piece of' other words can be used: a sheet of paper, a kilo of cheese, a jar of jam, a litre of petrol, a glass of water. All nouns referring to liquids are generally uncountable: beer, water, petrol, wine etc. Many foodstuffs are also uncountable: cheese, rice, bread, butter etc. I don't know about your mother language, but in Greece people have problems with two uncountable nouns in particular: money, hair. My hair is black. My money is safe in the bank!!! FYI: there are also words which are used only in the plural and when we want to count them, we have to resort to the following: trousers: these blue trousers are too tight. I have two pairs of blue trousers. Finally!! Rules for uncountable nouns. 1. they are grammatically singular and therefore are used with demonstrative adjectives in the singular [this, that] and with the pronoun it. 2. Being singular, they must be accompanied by a verb in the singular. 3, They never take the indefinite article [unless in conjunction with phrases like 'piece of' etc.] 4. They can be used with the definite article: The information you gave me has proved very useful. 5. They can not be used with: many, few, a few 6. They can be used with: much, a little, little, lots of, plenty of, some, any, no I have two pairs of blue trousers.