The comparative form of adjectives are typically classified into three degrees: comparative of superiority (e.g. “more beautiful”), comparative of equality (e.g. “as beautiful as”) and comparative of inferiority (e.g. “less beautiful”). There are two ways to construct comparative forms: morphological (i.e. with affixes) and syntactic (i.e. with adverbs). The comparative of equality expresses that referents have a property to an equal degree. Both in Persian and English, there is no morphological way to construct the comparative of equality. Both languages use adverbial constructions for this purpose.
Nominal Form of an Adjective
In Persian, you can convert an adjective to a noun by adding the suffix ی (“-i”) to it. The result noun is called the nominal form of the adjective. For example, خوبی (goodness) is the nominal form of خوب (good).
When adjectives ends in a vowel other than “-e”, the epenthetic consonant “-y-” is added before the suffix “-i” to resolve vowel hiatus.
When adjectives end in “-e”, usually a “-g-” appears before the suffix. It belongs to the older form of the word and is not the result of epenthesis.
To make a comparison of equality e.g. “as good as”, the nominal form of the adjective is placed in the following pattern. Since nominal forms always end in “-i”, the genitive marker “-e” always appears as “-ye”.
|Preposition به (“be”)||Nominal form||genitive marker -ye|
as good as
as bad as
as beautiful as
as fresh as
|سارا به زیبایی خواهرش است
⟨sârâ be zibâyi-ye xwâhar-aš ast⟩
Sarah is as beautiful as her sister