Turkic languages possess numerous interjections, expressive exclamations mostly consisting of single words. They may stand in isolation, forming self-contained utterances, but are often placed before sentences and followed by a pause. They can also occur as parenthetical elements inserted into sentences. The interjections constitute a heterogeneous category, which partly overlaps with others. Some interjections are indistinguishable from adverbs. It is difficult to establish crosslinguistic equivalents in a systematic way. Interjections of Arabic-Persian origin occur in all Turkic languages of the Islamic cultural sphere. Most other interjections vary considerably. Polysyllabic interjections tend to be accentuated on their first syllable (Chapter 50).