the

Used before a noun when it is clear which person or thing you mean, because it was mentioned before or is known.

• I bought a shirt and a hat, but the hat was too small.
  Bir gömlek ve bir şapka aldım ama şapka çok küçüktü.
• Can you close the door, please?
  Kapıyı kapatır mısın, lütfen?

Used before a noun when there is only one of that thing.

• The sun rises in the east and sets in the west.
  Güneş doğudan doğar, batıdan batar.
• Who was the first person to walk on the moon?
  Ay'da yürüyen ilk insan kimdi?

Used before a noun that is followed by words saying exactly which one you mean.

• The man in the blue coat is my uncle.
  Mavi paltolu adam benim amcam.
• Please give me the book you borrowed yesterday.
  Dün ödünç aldığın kitabı bana verir misin lütfen?

Used before a singular noun to talk about a type of thing in general, or before musical instruments.

• The computer has changed the way we work.
  Bilgisayar çalışma şeklimizi değiştirdi.
• My daughter is learning to play the guitar.
  Kızım gitar çalmayı öğreniyor.

Used before an adjective to refer to all the people of that kind.

• The young often have different ideas from the old.
  Gençlerin fikirleri çoğu zaman yaşlılarınkinden farklıdır.
• The city opened a new centre to help the homeless.
  Şehir, evsizlere yardım etmek için yeni bir merkez açtı.

Used before superlatives, ordinal numbers and words such as only, same and next.

• This is the best pizza I have ever eaten.
  Bu, şimdiye kadar yediğim en güzel pizza.
• She was the first person to arrive at the party.
  Partiye ilk gelen kişi oydu.

Used before some names, such as rivers, seas, mountain ranges and plural country names.

• The Nile is the longest river in Africa.
  Nil, Afrika'nın en uzun nehridir.
• My cousin has lived in the United States for years.
  Kuzenim yıllardır Amerika Birleşik Devletleri'nde yaşıyor.

Used before a decade to mean the years in it, such as the 1990s.

• My parents met in the eighties at university.
  Annemle babam seksenlerde üniversitede tanıştı.
• Mobile phones became popular in the 1990s.
  Cep telefonları 1990'larda yaygınlaştı.

Used twice with comparatives to show that two things change together.

• The more you practise, the better you get.
  Ne kadar çok pratik yaparsan o kadar iyi olursun.
• The sooner we leave, the sooner we'll arrive.
  Ne kadar erken çıkarsak o kadar erken varırız.

Used after by to show the unit in which something is paid, sold or measured.

• In this market, cherries are sold by the kilo.
  Bu pazarda kiraz kiloyla satılıyor.
• We pay the babysitter by the hour.
  Bebek bakıcısına saat başına ödeme yapıyoruz.

Used, with strong stress, to show that someone or something is the best or most famous of its kind.

• This is the place to eat fish in Izmir.
  İzmir'de balık yenecek asıl yer burası.
• For many skiers, it is the mountain to visit.
  Birçok kayakçı için gidilmesi gereken asıl dağ burası.