used to form a negative phrase after verbs like "be", "can", "have", "will", "must", etc., usually used in the short form "n't" in speech:

• i won't tell her
• i can't go
• don't you like her?
• it isn't hard (= it is easy)
• i'm just not interested
• he's not bad-looking (= he is fairly attractive)
• he's not as tall as his father

used before a noun to refer to a single thing or person that has not been mentioned before, especially when you are not referring to a particular thing or person:

• i've bought a car
• she's got a boyfriend
• there was a sudden loud noise
• what a shame that you couldn't go to the party
• i heard a child crying
• is he a friend of yours (= one of your friends)?

existing in fact and not imaginary:

• assuring the patient that she has a real and not imaginary problem is the first step
• there is a very real threat that he will lose his job

someone who is skilled in playing music, usually as a job:

• the concert features dancers and musicians of all nationalities