чуқуртарин: deepest
Baikal is the deepest lake in the world.
Дар байни уқёнусҳо уқёнуси Ором калонтарин ва чуқуртарин аст.
Among the oceans, the Pacific Ocean is the biggest and deepest.
Bonus:
synonym: амиқ
чуқур: deep
чуқуртар: deeper
Resources for learning the Tajik language
Bonus:
synonym: амиқ
чуқур: deep
чуқуртар: deeper
Bonus:
In Tajik they usually use the word бозичаҳо (toys) for tree ornaments.
ранг: colour
Adding the suffix ин changes a noun into an adjective. Another example of this is сангин.
рангинкамон: rainbow
Bonus:
дили сангин: stone heart, heart of stone
асри сангин: Stone Age (аср: century)
You can add the suffix ин to some nouns to make them into adjectives –
санг – сангин: stone – stone (adj.), stony
ранг – рангин: colour – colourful
чирк – чиркин: dirt – dirty
чӯб – чӯбин: wood – wooden
мармар – мармарин: marble – marble (adj.), made of marble
If the noun ends in a vowel then the suffix is гин
нуқра – нуқрагин: silver – silver (adj.), made of silver
тилло – тиллогин: gold – golden, made of gold
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Synonym: шодӣ
The adjective, хурсанд, is made into a noun by adding the suffix ӣ.
хурсанд: happy, joyful
хурсандӣ: happiness, joy
Other examples of changing an adjective into a noun by adding the suffix ӣ:
ором, оромӣ: peaceful, peacefulness
сер, серӣ: full, fullness
миннатдор, миннатдорӣ: grateful, gratefulness
Here are a couple more examples. If the adjective ends in a vowel, the suffix is гӣ:
гурусна, гуруснагӣ: hungry, hunger
ташна, ташнагӣ: thirsty, thirst
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Synonyms: хубтар, нағзтар
A quick google search shows that беҳтар is used more often than хубтар and нағзтар (at least on the internet).
Беҳтар is the comparitive form of беҳ (good). Synonyms for беҳ are хуб and нағз.
Adding the suffix -ӣ to a noun makes it an adjective.бодҳои мавсимӣ: seasonal winds
коргари мавсимӣ: seasonal worker
парандагони мавсимӣ: seasonal (migratory) birds
For an intermediate lesson on comparatives and superlatives download this pdf: Comparatives and Superlatives.