and , and and were often conflated, but in some spellings, was distinguished from by rotating the kasra 90° and was distinguished from by writing the damma backwards. Several Swahili consonants do not have equivalents in Arabic, and for them, often no special letters were created unlike other languages. Instead, the closest Arabic sound is substituted. Not only did that mean that one letter often stands for more than one sound, but also writers made different choices of which consonant to substitute. Below are some of the equivalents between Arabic Swahili and Roman Swahili: That was the general situation, but conventions from Urdu were adopted by some authors so as to distinguish aspiration and from : 'gazelle', 'roof'. Although it is not found in Standard Swahili today, there is a distinction between dental and alveolar consonants in some dialects, which is reflected in some orthographies, for example in 'to meet' vs. 'to be satisfied'. A k with the dots of y, , was used for ch in some conventions; ky being historically and even contemporaneously a more accurate transcription than Roman ch. In Mombasa, it was common to use the Arabic emphatics for Cw, for example in (standard ) 'we' and (standard ) 'head'. Particles such as are joined to the following noun, and possessives such as and are joined to the preceding noun, but verbs are written as two words, with the subject and tense–aspect–mood morphemes separated from the object and root, as in "he who told me". Grammar Noun classes Swahili nouns are separable into classes, which are roughly analogous to genders in other languages. In Swahili, prefixes mark groups of similar objects: marks single human beings ( 'child'), marks multiple humans ( 'children'), marks abstract nouns ( 'childhood'), and so on. And just as adjectives and pronouns must agree with the gender of nouns in some languages with grammatical gender, so in Swahili adjectives, pronouns and even verbs must agree with nouns. This is a characteristic feature of all the Bantu languages. Semantic motivation The ki-/vi- class historically consisted of two separate genders, artefacts (Bantu class 7/8, utensils and hand tools mostly) and diminutives (Bantu class 12/13), which were conflated at a stage ancestral to Swahili. Examples of the former are kisu "knife", kiti "chair" (from mti "tree, wood"), chombo "vessel" (a contraction of ki-ombo). Examples of the latter are kitoto "infant", from mtoto "child"; kitawi "frond",