Араб әліпбиінде дауысты әріптерді белгілеу және екі рет жазылуы

Arabic diacritic marking gemination

Shaddah (شَدّة , "[sign of] emphasis", also called by the verbal noun from the same root, tashdid تشديد "emphasis") is one of the diacritics used with the Arabic alphabet, indicating a geminated consonant. 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 = 'pomegranates'.

Consonant length in Arabic is contrastive: دَرَسَ means "he studied", while دَرَّسَ means "he taught"; بَكى صَبي means "a youth cried" while بَكّى الصَّبي means "the youth was made to cry". A consonant may be long because of the form of the noun or verb; e. g., the causative form of the verb requires the second consonant of the root to be long, as in above, or by assimilation of consonants, for example the of the Arabic definite article al assimilates to all dental consonants, e. g. (الصّبي) instead of , or through metathesis, the switching of sounds, for example أَقَلّ 'less, fewer' (instead of *أَقْلَل ), as compared to أَكْبَر 'greater'. A syllable closed by a 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 iʻrāb, ) as opposed to أَكْبَر , مَحَبّة "love, agape" as opposed to مَعْرِفة '(experiential) knowledge'. In Arabic verse, when scanning the meter, a syllable closed by a long consonant is counted as long, just like any other syllable closed by 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.