Usually, the best way to identify a countable noun (when reading English texts, for example) is to notice whether the noun has an "a" before it (singular) or an "s" (plural). These nouns can be counted: a book, two books, three books, many books, several books, a couple books (OK! it has an 'S'), a few books, a dozen books... If the noun is uncountable, usually there is no 'a' or 's' and it has a singular verb: There is bread on the table, there is heavy traffic in the street... Notice certain phrases like 'A LOT OF' or 'A LITTLE' are not singular and can be used with countable and uncountable nouns: I don't have a lot of money but I have a lot of books. (money=uncountable, book=countable) I have a lot of bread but only a little butter. (both bread and butter are uncountable)

check in the dictionary

Countable words (nouns) usually refer to things and uncountable words (nouns) are thought of as wholes which is a bit tricky, this is why I would like to offer you this page, http://www.engvid.com/english-resource/countable-and-uncountable-nouns/ I hope this will help you out :) Have a nice day !