Tashdid

Shaddah (Arabic: شَدّة‎‎ shaddah "[sign of] emphasis", also called by the verbal noun from the same root, tashdid تشديد tashdīd "emphasis") is one of the diacritics used with the Arabic alphabet, marking a long consonant (geminate). It is functionally equivalent to writing a consonant twice in the orthographies of languages like Latin, Italian, Swedish, and Ancient Greek, and is thus rendered in Latin script in most schemes of Arabic transliteration, e.g. رُمّان = rummān 'pomegranates'.

In shape, it is a small letter س s(h)in, standing for shaddah. It was devised for poetry by al-Khalil ibn Ahmad in the eighth century, replacing an earlier dot.

When a shadda is used on a consonant which also takes a fatḥah /a/, it is written above the shaddah, while if it had a kasrah (a dash below the consonant indicating that it takes a short /i/ as its vowel), the kasrah is written between the consonant and the shaddah, under the shaddah, rather than in its normal place.

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