This kana is used in vocabulary and has a special role as a small 『っ』 (sokuon) to indicate a geminate consonant, but when written as a full-sized 『つ』, it is pronounced as 『つ』 (tsu). For example, in the word 『つくえ』 (tsukue, 'desk'), it is part of the noun. As a particle, it is not commonly used, so focus on its sound in words. Note that small 『っ』 is written differently and indicates a pause or doubled consonant, e.g., in 『かった』 (katta, 'bought').