The superlative enclitic is[tag resources comparative_superlative_053] ترین. [/tag] The superlative adjective must invariably be followed by a noun directly, and without taking any preposition. While the subject of the sentence is specific (such as a hyponym), the noun that the tarin-phrase precedes normally is generic:

[tag resources superlative_01] .گربه زیرک‌ترین حیوان است[/tag]
gorbe ziraktarin heyvān ast
“Cats are the smartest of animals.”

[tag resources superlative_02] .آبادان زیباترین شهر ایران است[/tag]
ābādān zibātarin šahr-e irān ast
“Abadan is the most beautiful city of Iran.”

[tag resources superlative_03] .شهرزاد بهترین شاگرد این کلاس است[/tag]
šahrzād behtarin šāgerd-e in kelās ast
“Sheherzade is the best student in this class.”

A very specific “partitive” construction is formed by pluralizing the generic noun and connecting it to the preceding superlative adjective, using the ezāfe link:

[tag resources superadj_01] .آبادان زیباترینِ شهرهای ایران است[/tag]
ābādān zibā tarin-e šahr hyā-e irān ast
“Abadan is the most beautiful city of Iran.”
Literally, “Abadan is the most beautiful of the cities of Iran.”

A specific construction with the phrase[tag resources comparative_superlative_058] بیش از پیش [/tag] biš az piš (literally ‘more than before’) equates the English adverbial ‘more than ever’ and adjectival ‘more…than ever’:

[tag resources superadj_02] .این دانش‌آموز بیش از پیش ترقّی کرده است[/tag]
in dāneš āmuz biš az piš taraqqi karde ast
“This student has progressed more than ever.”

[tag resources superadj_03] .آن شهر بیش از پیش آباد شده است[/tag]
ān šahr biš az piš ābād šode ast
“That city has flourished more than ever.”

[tag resources comparative_superlative_061] .شیرین بیش از پیش خوشحال است[/tag]
širin biš az piš xošhāl ast
“Shirin is happier than ever.”

Since suffixes and postpositions cannot attach to the Silent /h/, neither tar nor tarin may be attached to it, even in the writings of those who opt to attach these suffixes to other words:[tag resources superadj_04] بچّه‌تر [/tag] bacce tar‘more childish’ and[tag resources superadj_05] بچّه‌ترین [/tag]bacce tarin ‘the most childish,’ never بچّهتر, بچّهترین; خسته‌تر xaste tar ‘more tired’ and خسته‌ترین xaste tarin ‘the most tired’, never خستهتر, خستهترین.

Even if we opt to connect the comparative and superlative enclitics, we better write them separately if the adjective ends in a terminal ـت –t: [tag resources comparative_superlative_064]سخت‌تر [/tag] ‘harder,’ not سختتر; درشت‌تر ‘larger,’ not درشتتر.

The superlatives of[tag resources comparative_superlative_065] خوب [/tag] and[tag resources comparative_superlative_067] زیاد /[/tag] [tag resources comparative_superlative_066] بسیار [/tag]are [tag resources comparative_superlative_068]بهترین [/tag] and[tag resources comparative_superlative_069] بیشترین. [/tag] Occasionally in the colloquial dialect one would hear[tag resources comparative_superlative_070] خوبترین [/tag] and[tag resources comparative_superlative_071] زیادترین.[/tag]

While normally the preposition for the second term of comparison is[tag resources comparative_superlative_072] از, [/tag] a different construction is used with[tag resources comparative_superlative_073] تا [/tag] in vary specific situations, as follows:

If we opt to place the second term of the comparison after the verb:

[tag resources superadj_06] .این بچهّ بیشتر غذا خورد تا شما[/tag]
in bacce bištar γazā xord tā šomā
“This child ate more than you (did).”

[tag resources superadj_07] .هفت بیشتر است تا چهار[/tag]
haft bištar ast tā cahār
“Seven is more than four.”

[tag resources superadj_08] .برای این کار کامران بهتر است تا محمّد[/tag]
barā-ye in kār kāmrān behtar ast tā mohammad
“Kamran is better for this job than Mohammad.”

When the second term of the comparison is the object of the sentence—direct or indirect:

[tag resources superadj_09] .با او بیشتر حرف زدم تا با تو[/tag]
bā u bištar harf zadam tā bā to
“I talked with him/her more than I did with you.”

[tag resources superadj_10] .کامبیز را بیشتر دوست داشت تا کورش را[/tag]
kāmbiz rā bištar dust dāšt tā kuroš rā
“He/she liked/loved Kambiz more than Koorosh.”
“He/she liked/loved Kambiz more than he/she loved Koorosh.”

When the quality in something is less than expected, then a lower quality material (as a noun) follows the comparative adjective and the expected quality follows the tā:

[tag resources superadj_11].این بیشتر آب است تا شراب[/tag]
in bištar āb ast tā šarāb
“This is more [like] water than wine.”
“This is more water than [it is] wine.”

[tag resources superadj_12].این بیشتر قاطر است تا اسب[/tag]
in bištar qāter ast tā asb
“This is more a mule than a horse.”