Conjunction 'ki' vs. Relative Suffix '-ki' in Turkish

In Turkish, ki exists in two distinct grammatical identities that must never be confused in spelling or function:

1. The Persian-origin Conjunction ki (written separately): Functions as a subordinating conjunction meaning 'that', 'so... that', or 'which'. It introduces clause complements in European-style left-to-right syntax: Biliyorum ki sen haklısın (I know that you are right); Öyle yoruldum ki hemen uyudum (I was so tired that I fell asleep immediately). It is always written as an independent separate word. 2. The Invariable Suffix -ki (written attached): An exceptional Turkish suffix that does not undergo vowel harmony (always -ki, except in dünkü yesterday's and bugünkü today's). It has two main roles: - Adjectivizing suffix on locatives: attaches to the locative case (-de/-da) to form a relative adjective meaning 'the one located in/on': masada-ki kitap (the book on the table), evde-ki hesap (the budget at home), sokakta-ki arabalar (the cars in the street). - Pronominal possessive suffix on genitives: attaches to genitive pronouns to mean 'mine, yours, his': benim-ki (mine / the one belonging to me), senin-ki (yours), Ahmet'in-ki (Ahmet's one).

Confusing the detached conjunction ki with the attached suffix -ki is one of the most frequent spelling errors in both native and learner Turkish.