Participles (sıfat-fiiller or ortaçlar) are verb forms that function as adjectives, describing nouns. They can also form the basis of relative clauses.

1. Present Participle: -en / -an

Describes someone/something that is doing or does the action ("the one who ...-s", "...-ing"). Follows A-Type vowel harmony. If the stem ends in a vowel, buffer -y- is used: -yen / -yan.

• gelen adam (the man who is coming / the coming man)
• koşan çocuk (the child who is running / the running child)
• okuyan öğrenci (the student who reads / the reading student)

2. Past Participle / Narrative Participle: -miş / -mış / -muş / -müş

Describes someone/something that has done the action or has undergone it (often with an indirect/reported sense, "the one who apparently ...-ed", "the ...-ed one"). Follows I-Type vowel harmony.

• gelmiş misafir (the guest who has (apparently) come)
• okunmuş kitap (the read book / the book that has been read)
• yorgun düşmüş asker (the soldier who had fallen tired)

3. Future Participle: -ecek / -acak

Describes someone/something that will do the action ("the one who will ...", "the future ..."). Follows A-Type vowel harmony. Buffer -y- after vowel stems: -yecek / -yacak. The final 'k' softens to 'ğ' when it takes a vowel suffix (e.g. in possessive constructions).

• gelecek yıl (the coming year / next year)
• yapılacak iş (the work that will be done / work to be done)
• okuyacağım kitap (the book that I will read) (Note: okuyacak + -ım → okuyacağım)

4. The -dik / -dık / -duk / -dük (and -tik / -tık / -tuk / -tük) Participle

This is a very versatile past/present participle, often used in relative clauses with possessive suffixes to indicate the subject of the verb within the clause. It refers to a specific action done by someone. It translates roughly to "the (noun) that (someone) did/does/is doing".

• Benim gördüğüm film (The movie that I saw) (gör- + -dük + -üm)
• Senin yazdığın mektup (The letter that you wrote) (yaz- + -dık + -ın)
• Onun yaptığı yemek (The food that he/she made) (yap- + -tık + -ı)

This participle can take case endings as well: sevdiğim kıza (to the girl I love).

There are other participles, but these are the most fundamental ones.