Shadda

Shadda (Arabic شَدَّةٌ "[sign of] emphasis", also called by the verbal noun to the same root, Tashdid تشديد "emphasis"), is one of the diacritics (Harakat) 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. رُمَّان = "pomegranate".

Consonant length in Arabic is contrastive: دَرَسَ means "he studied" while دَرَّسَ means "he taught"; بَكَى صَبِيّ means "a youth cried" while بَكَى الصَّبِيّ means "the youth cried". A consonant may be long because of the form of the noun or verb, e.g. the causative form of the verb requires the 2nd consonant of the root to be long, as in above, or by assimilation of consonants, for example the of the Arabic definite article assimilates to all dental consonants, e.g. instead of , or through haplology, that is, the elision of two identical consonants, for example أَقَلّ "less, fewer" instead of أَقْلَل , as compared to أَكْبَر "greater".

The syllable closing with the long consonant is made a long syllable. This affects both stress and prosody. Stress falls on the first long syllable from the end of the word, hence أَقَلّ (or, with i`rab, ) as opposed to أَكْبَر , مَحَبَّة maḥábba "love, agape" as opposed to مَعْرِفَة "[experiential] knowledge". In Arabic verse, when scanning the meter, the syllable closing with the long consonant is counted as long, just like any other syllable closing with a consonant or a syllable ending in a long vowel: أَلا تَمْدَحَنَّ "Will you not indeed praise...?" is scanned as : short, long, long, short, long, short.