(الذي), allatī (التي), etc. in Arabic. This is the view of Ibn Hisham and Al-Akhfash al-Akbar. This opinion is in harmony with the form of the general relative pronoun (alli, illi, al) in most Arabic dialects nowadays. If this view is correct, this aberrant al- does not follow the sun and moon letters rule. Al- may also be used to turn verbs in the imperfect, passive state into adjectives in a limited set of circumstances. This is employed to show ability/possibility, or with the use of another particle ("-la-"), inability/impossibility as is related to the definite word the resulting adjective modifies. Examples: Al-yurā : the see-able; al-yu'kal : the edible; al-la-yurā : the un-see-able; al-la-silkī : the wire-less [device]; etc. When al- occurs in places where we would not normally expect it, it is considered extra as far as grammar and lexicology are concerned. This is the view of al-Kisā’ī. Al- is used by poets to complete the meter of the verse under poetic license. This is the view of Ibn Malik, the author of the Alfiyyah; it is rejected by the author of the Khizānat al-Adab. At the beginning of nouns (ism) The terms noun and ism have been used synonymously in this section Because nouns require the functions provided by al- (namely definiteness), al- is prefixed to them. Ism, as defined in classical Arabic grammar, includes all parts of speech save particles and verbs: nouns, pronouns, adjectives, adverbs, etc. As a general rule, al- may be prefixed to any ism, regardless of gender, plurality, grammatical case, etc. However, this rule has some pathological caveats. That is, there are some nouns that al- may never be prefixed to, and there are others that al- must always be prefixed to. Prohibited prefixation Nouns that do not inflect for definiteness The definite article al- is not typically prefixed to nouns that do not inflect for definiteness. Examples include the interrogative man 'who'. Already definite nouns The definite article al- is not typically prefixed to nouns that are already definite. Examples include personal pronouns, relative pronouns, demonstrative pronouns, nouns already prefixed with al-, etc. Exceptions to this include the prefixation of al- to the relative pronoun (see #Extra) and to proper nouns (see #At the beginning of names). As a concrete example, al- has been recorded at the beginning of a demonstrative pronoun, as in the following poetic verse: The genitival construction