an

Used instead of a before a vowel sound, when you mention something for the first time.

• I eat an apple every morning before work.
  Her sabah işe gitmeden önce bir elma yerim.
• There's an old castle at the top of the hill.
  Tepenin üstünde eski bir kale var.

Used before a vowel sound to say what someone or something is, such as a job.

• My brother is an engineer at a car factory.
  Ağabeyim bir otomobil fabrikasında mühendis.
• It was an interesting idea, but it was too expensive.
  İlginç bir fikirdi ama çok pahalıydı.

Used to mean each or every with rates and periods of time, such as an hour.

• Parking here costs three pounds an hour.
  Burada park ücreti saat başına üç sterlin.
• The train was travelling at 300 kilometres an hour.
  Tren saatte 300 kilometre hızla gidiyordu.

Used to mean one, with numbers and periods of time that begin with a vowel sound.

• The film lasts about an hour and a half.
  Film yaklaşık bir buçuk saat sürüyor.
• I'll be ready in an hour, so please wait.
  Bir saate hazır olurum, lütfen bekle.

Used to mean any member of a group, when saying what is true of every member.

• An owl can turn its head almost all the way round.
  Baykuş başını neredeyse tamamen geriye çevirebilir.
• An honest person always tells the truth.
  Dürüst bir insan her zaman doğruyu söyler.

Used after what and such before a vowel sound to express a strong feeling about something.

• What an amazing view from the top of the tower!
  Kulenin tepesinden ne muhteşem bir manzara!
• It was such an easy question that everyone got it right.
  Öyle kolay bir soruydu ki herkes doğru bildi.

Used before a drink or a dish to mean one glass, cup or portion of it.

• Can I have an orange juice, please?
  Bir portakal suyu alabilir miyim, lütfen?
• The children each had an ice cream after lunch.
  Çocukların her biri öğle yemeğinden sonra bir dondurma yedi.