Neither suffixes nor independent words are used for comparative adjective marking (e.g. English -er in bigg-er or French plus in plus grand). However, in Juba Arabic, Arabic derived forms are attested, which are specialized in the formation of comparative and superlative adjectives, called elatives; In order to form superlatives and comparatives in Arabic, in fact, the consonants of the adjective's root are placed according to a aCCaC scheme, where a is the vowel and C the consonant. Accordingly, the superlative form of kabir 'big' will be akbar 'bigger'.
The occurrence of such forms in Juba Arabic can be interpreted either as Arabic morphological traces (which might be rooted in lexicalization processes in Juba Arabic), or as outcomings of the present levelling process towards Sudanese Arabic. We lack historical data.
Source: Manfredi 2005: 207
Source: Manfredi 2005: 207
Source: Miller 1993: 167
Source: Manfredi 2005: 209
Source: Manfredi 2005: 209