The Italian indefinite article (l'articolo indeterminativo) corresponds to English a/an and is used with singular nouns. It also corresponds to the number one.
When the noun to which the article applies is a masculine noun then "a/an" can be translated as "un", or "uno", if the article applies to a feminine noun then the article that has to be used is "una". As the definite articles, there are some rules to understand the use of these articles:
|un treno e una bicicletta||A train and a bicycle|
|un aeroplano e un’automobile||An airplane and a car|
|uno stadio e una stazione||One(an) stage and one(a) station|
When plural nouns are indefinite, they simply do not use an article, or they use the partitive form: i.e. cats (no article) or some cats (partitive), coins or some coins (partitive), etc. Partitive will be dealt with further on, so for the time being simply disregard its use.