next word starts with consonant sound: a book / a university

When you talk about sth unspecific/ in general:

could you give me a pen please?

In professions: a nurse

 

 

next word starts with a vowel sound: an orange / an hour

When you talk about sth unspecific/ in general: could you give me an apple please?

in professions: an internet programmer

 

 

When you talk about sth specific/ you know which one

specific season: The winter of 2006

 a building: let's meet at the hospital

Instruments: He plays the piano

 

 

Things or people in general: Life is good/ Most people like George

in seasons: in winter/SPRING

in meals: lunch is nice today (but with adj: a very nice lunch)

when there is only one: W Alexander is king of Holland

function of a building: He's in hospital (patient)

names of streets : Main street