Turkish has a negative concord item (NCI) katiyen ‘never’ that functions as an adverb and generally requires the presence of sentential negation in the sentence (Kelepir, 2001; Göksel and Kerslake, 2005). Yakut-Kubaş (2022), in a recent work, on the other hand, argues that katiyen can also appear in certain non-negative structures. She proposes that these two uses of the word in negative and non-negative structures can be captured in a unified manner if we assume that katiyen is an element that marks the highest degree of subjective certainty expressed by the speaker. In that sense, this pragmatic function is argued to bring these two uses together. In this work, based on a large-scale corpus work that includes 648 sentences containing the word, I will show that katiyen is essentially ambiguous that has distinct semantic and pragmatic meanings with different syntactic distributions. First, it is primarily an NCI that requires the presence of sentential negation at all times and is interpreted as ‘never’ or ‘in no way’. This use accounts for 619 instances of katiyen in the corpus data and shows that more than 95% of the time it predominantly functions as an NCI. Second, it can appear in two structurally non-negative structures: (i) 14 instances of syntactically and semantically positive structures that comprise less than 1 percent of the data and katiyen having the meaning ‘definitely’ and (ii) 13 instances of syntactically non-negative but semantically negative structures that account for less than 1 percent of the data and katiyen being interpreted as ‘strictly’. Here it is used to modify a prohibitive predicate but does not necessarily mark the subjective certainty. I conclude that different uses of katiyen indicate significant structural, semantic and pragmatic distinctions, which is in contrast with recent claims that its pragmatic use is the same in each case.