Turkish Buffer Letters: y, s, n, ş

Turkish never lets two vowels stand next to each other across a suffix boundary. When a word ends in a vowel and the suffix starts with one, a bridge letter is inserted between them. Four letters do this job, and each has its own place.

y is the everyday bridge: it comes before the dative -e/-a, the accusative -i and the copula -im: araba + a → arabaya, kapı + ı → kapıyı, öğrenci + im → öğrenciyim. s appears only before the third-person possessive -i: anne + i → annesi, araba + ı → arabası.

n links a possessive to the case suffix after it, and joins bu, şu, o to any suffix: annesi + de → annesinde, bu + u → bunu, o + a → ona. ş appears only in distributive numbers: iki + er → ikişer. After a consonant there is no bridge at all: ev + e → eve.