Ordinal Numbers — Persian Grammar

Ordinals - first, second, third - are built from the plain numbers with a single ending, and they come in two shapes depending on where they stand.

The Ending ـُم (-om)

Add ⁧ـُم⁩ (-om) to a number and you have the ordinal.

Three are irregular and have to be learned:

The plain ordinal in ⁧ـُم⁩ (-om) follows its noun, hooked on with an ezafe like any other adjective.

⁧روزِ دُوُّمِ مَن⁩
ruz-e dovvom-e manruz-e dovvom-e manrvz-a dvm-a mn
my second day
⁧فَرزَندِ پَنجُمِ مَن⁩
farzand-e panjom-e manfarzand-e panjom-e manfrznd-a pnjm-a mn
my fifth child
⁧طَبَقِه‌یِ شانزدَهُم⁩
ṭabaqe-ye šânzdahomtabaqe-ye shânzdahomṭbqh-y šanzdhm
the sixteenth floor

Add ⁧ین⁩ (-in) and the ordinal moves in front of the noun instead, with no ezafe.

⁧دُوُّمین هُتِلِ بَرتَرِ شَهر⁩
dovvomin hotel-e bartar-e šahrdovvomin hotel-e bartar-e shahrdvmyn htl-a brtr-a šhr
the second-best hotel in the city
⁧سِوُّمین اِنسانِ رویِ ماه⁩
sevvomin ensân-e ru-ye mâhsevvomin ensân-e ru-ye mâhsvmyn ansan-a rv-y mah
the third person on the moon
⁧اَوَّلین روزِ کاریِ شُما⁩
avvalin ruz-e kâri-ye šomâavvalin ruz-e kâri-ye shomâavlyn rvz-a kary-y šma
your first working day

Both say the same thing. The choice is one of position and of rhythm, not of meaning.

Dates use the plain ordinal in ⁧ـُم⁩ (-om), with the ordinal attached to the day and the month following.

⁧جُمعِه سیزدَهُمِ مِه⁩
jomʿe sizdahom-e mejom'e sizdahom-e mejmʿh syzdhm-a mh
Friday the thirteenth of May
⁧دَوازدَهُمِ اوت⁩
davâzdahom-e utdavâzdahom-e utdvazdhm-a avt
the twelfth of August
⁧اِمروز اَوَّلِ مِه اَست.⁩
emruz avval-e me astemruz avval-e me astamrvz avl-a mh ast
Today is the first of May.

In the course

14 of the course's 500 sentences use this, the first in lesson 331. A few of them, with the words “Ordinal Numbers” is about in bold:

اولین برداشت من این است که او بسیار باهوش است.
avvalin bardâšt-e man in ast ke u besiyâr bâhuš ast.avvalin bardâsht-e man in ast ke u besiyâr bâhush ast.avlyn brdašt mn ayn ast kh av bsyar bahvš ast.
My first impression is that she is very smart.
Lesson 333
شما اولین کسی هستید که متوجه شدید!
šomâ avvalin kasi hastid ke motevajje šodid!shomâ avvalin kasi hastid ke motevajje shodid!šma avlyn ksy hstyd kh mtvjh šdyd!
You are the first person to notice!
Lesson 337

Loading comments…