Persian fractions are built from a cardinal numerator + ordinal denominator: دو سوم “two thirds,” literally “two third.” نیم supplies the everyday word “half,” while درصد follows a number to express a percentage: بیست درصد “twenty percent.”
These expressions quantify either a unit, as in نیم ساعت, or a portion of a known whole, as in دو سوم کارکنان. The shape of that whole matters for agreement: a human group normally triggers a plural verb, while a mass or aggregate commonly takes singular agreement.
Half: نیم and نصف
نیم is the ordinary, productive word before a unit or noun: نیم ساعت، نیم کیلو، نیمهی شب. It packages one half of the following unit. نصف is also current and often foregrounds an equal division of a concrete or abstract whole: نصف کیک، نصف بودجه. In many contexts they overlap, but نیم ساعت is the fixed natural expression for “half an hour.”
تا رسیدن اتوبوس نیم ساعت وقت داریم.
tâ residan-e otobus nim sâ'at vaqt dârim.
We have half an hour until the bus arrives. (neutral standard)
نصف بودجه برای تعمیر ساختمان مصرف شد.
nesf-e budje barâ-ye ta'mir-e sâkhtemân masraf shod.
Half the budget was spent on repairing the building. (formal-neutral; aggregate with singular agreement)
یک نان را نصف کردیم و هر کدام نیمهای برداشتیم.
yek nân râ nesf kardim va har kodâm nime-i bardâshtim.
We cut one loaf in half, and each took one half. (neutral conversation)
The noun نیمه “half; half-section” can stand independently and take ordinary Persian morphology, as نیمهای does. Do not treat every English half as the same part of speech.
Productive fractions
For a productive fraction, use a cardinal numerator followed by the short ordinal denominator. The denominator remains singular in form.
| Value | Persian | Reading | Common alternative |
|---|---|---|---|
| 1/2 | یک دوم | yek dovvom | نیم، نصف |
| 1/3 | یک سوم | yek sevvom | ثلث in formal or fixed uses |
| 2/3 | دو سوم | do sevvom | productive form |
| 3/4 | سه چهارم | se chahârom | سه ربع in some fixed contexts |
| 5/8 | پنج هشتم | panj hashtom | productive form |
The denominator says how many equal parts define the whole; the numerator says how many of those parts are selected. English expresses this through plural thirds in two thirds. Persian does not pluralize سوم: the number دو already counts the fractional parts.
دو سوم مسیر را تا پیش از ظهر طی کردیم.
do sevvom-e masir râ tâ pish az zohr tey kardim.
We covered two thirds of the route before noon. (neutral standard)
برای این دستور غذا سه چهارم پیمانه شیر لازم است.
barâ-ye in dastur-e ghazâ se chahârom-e peymâne shir lâzem ast.
This recipe requires three quarters of a cup of milk. (neutral; fraction of a measure unit)
پنج هشتم اعضای شورا به پیشنهاد رأی مثبت دادند.
panj hashtom-e a'zâ-ye shurâ be pishnehâd ra'y-e mosbat dâdand.
Five eighths of the council members voted for the proposal. (formal; human plurality with plural agreement)
Consonant-final ezâfe is unwritten in دو سوم مسیر and پنج هشتم اعضا, but it is pronounced. The fraction can alternatively select from an explicit set with از: دو سوم از کارکنان. This longer partitive is useful when the source set is contrastive or already definite.
Lexical ثلث and ربع
ثلث sols “one third” occurs in legal, financial, religious, and other (formal) set expressions. Everyday speakers usually choose transparent یک سوم. ربع rob' “one quarter” remains familiar from clock time and certain formal expressions, but productive calculation favors یک چهارم.
یک سوم مبلغ را امروز میپردازم و باقی را ماه بعد.
yek sevvom-e mablagh râ emruz mi-pardâzam va bâqi râ mâh-e ba'd.
I’ll pay one third of the amount today and the rest next month. (neutral standard)
در متن حقوقی، ثلث دارایی بهطور جداگانه محاسبه شده است.
dar matn-e hoquqi, sols-e dârâyi be-towr-e jodâgâne mohâsebe shode ast.
In the legal text, one third of the assets has been calculated separately. (formal/legal)
Do not import these Arabic-origin lexical fractions merely to sound educated. They are real Persian vocabulary, but their distribution is narrower than that of نیم and productive ordinal fractions.
Mixed numbers and singular measures
A whole number and a fraction are joined with numeric و: دو و نیم ساعت، سه و یک چهارم کیلو. The following measure noun remains singular, just as it does after an integer.
کارگاه دو و نیم ساعت ادامه داشت.
kârgâh do-o-nim sâ'at edâme dâsht.
The workshop continued for two and a half hours. (neutral standard)
برای دیوار سه و نیم لیتر رنگ خریدیم.
barâ-ye divâr se-o-nim litr rang kharidim.
We bought three and a half liters of paint for the wall. (neutral conversation)
The و here joins a whole component to its fractional remainder. It is not the same as a decimal separator, though دو و نیم and دو ممیز پنج can denote the same value in different registers and contexts.
Percentages with درصد
درصد follows its number: پنجاه درصد. In edited typography, the Persian percent sign is ٪, as in ۲۵٪; in speech, read the word درصد. A percentage can directly modify a quantity noun or select part of a group with ezâfe or از.
| Pattern | Example | Function |
|---|---|---|
| number + درصد | ۲۰ درصد | percentage value |
| percentage + noun | ۲۰ درصد تخفیف | amount of discount |
| percentage + ezâfe + group | ۲۰ درصد کارکنان | part of a named group |
| percentage + از + group | ۲۰ درصد از کارکنان | explicit partitive |
فروشگاه برای پرداخت نقدی ۱۵ درصد تخفیف میدهد.
forushgâh barâ-ye pardâkht-e naqdi pânzdah darsad takhfif mi-dahad.
The shop gives a 15 percent discount for cash payment. (neutral commercial usage)
هفتاد درصد از پاسخدهندگان گزینهی نخست را انتخاب کردند.
haftâd darsad az pâsokh-dahandegân gozine-ye nakhost râ entekhâb kardand.
Seventy percent of respondents chose the first option. (formal survey report; plural human agreement)
فقط ۴۰ درصد بودجه تا پایان تابستان مصرف شد.
faqat chehel darsad-e budje tâ pâyân-e tâbestân masraf shod.
Only 40 percent of the budget was spent by the end of summer. (formal; aggregate with singular agreement)
Agreement follows the selected referent. هفتاد درصد از پاسخدهندگان ... کردند refers to multiple people; چهل درصد بودجه ... مصرف شد packages an amount of money as one aggregate.
Equivalent values, different packaging
نیم، یک دوم، پنجاه درصد, and decimal صفر ممیز پنج can denote the same mathematical value, but they are not interchangeable in every sentence. نیم ساعت is everyday measurement; یک دوم نمونه is analytical; پنجاه درصد نمونه frames a statistic; صفر ممیز پنج is a decimal value suited to calculation.
غلظت محلول را از یک دوم به یک چهارم کاهش دادیم.
ghelzat-e mahlul râ az yek dovvom be yek chahârom kâhesh dâdim.
We reduced the solution’s concentration from one half to one quarter. (technical)
For place-value and digit-by-digit readings after a separator, see Decimals with ممیز. Its structural foundation is the cardinal system in Building Tens, Hundreds, and Thousands.
Common Mistakes
1. Pluralizing the denominator
❌ دو سومها مسیر را رفتیم.
Incorrect — the cardinal numerator already counts the fractional parts; the denominator stays singular.
✅ تا غروب دو سوم راه را پیمودیم.
tâ ghorub do sevvom-e râh râ peymudim.
By sunset we had covered two thirds of the way.
2. Reversing numerator and denominator
⚠️ برای دو سوم، اول سوم و بعد دو را میگوییم.
barâ-ye do sevvom, avval sevvom va ba'd do râ mi-guyim.
Grammatical sentence expressing the wrong rule — Persian says the cardinal numerator first and the ordinal denominator second.
✅ سهم ما سه پنجم کل درآمد است.
sahm-e mâ se panjom-e koll-e darâmad ast.
Our share is three fifths of the total income.
3. Putting درصد before its number
❌ درصد بیست هزینه کم شد.
Incorrect percentage order — the number precedes درصد.
✅ هزینهی حملونقل بیست درصد کاهش یافت.
hazine-ye haml-o-naql bist darsad kâhesh yâft.
Transportation costs decreased by twenty percent.
4. Pluralizing a measure after a mixed number
❌ کار دو و نیم ساعتها طول کشید.
Incorrect — a directly measured unit remains singular after a mixed number.
✅ بررسی پرونده دو و نیم ساعت زمان برد.
barrasi-ye parvande do-o-nim sâ'at zamân bord.
Reviewing the file took two and a half hours.
5. Giving singular agreement to a selected human plurality
❌ هشتاد درصد کارکنان موافق بود.
Incorrect in the intended collective-human reading — the selected employees are plural participants.
✅ هشتاد درصد کارکنان با تغییر برنامه موافق بودند.
hashtâd darsad-e kârkonân bâ taghyir-e barnâme movâfeq budand.
Eighty percent of the employees agreed with the schedule change.
Key Takeaways
- Use نیم for everyday measured halves and نصف when an equal division is salient.
- Build productive fractions as cardinal numerator + ordinal denominator: دو سوم، سه چهارم.
- Use lexical ثلث and ربع only where their formal or fixed-register distribution fits.
- Put درصد after the number and use Persian ٪ in numeric typography.
- Let the selected whole—not the visible fraction or percentage word—guide verbal agreement.
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Start learning Farsi →Related Topics
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- Ordinals with ام and امینA2 — Form and place Persian ordinals with postnominal or predicative ـم, prenominal ـمین, and the irregular first forms اول and اولین.
- Building Tens, Hundreds, and ThousandsA1 — Build and pronounce exact Persian cardinals above twenty with linking و, irregular round numbers, and the scale words هزار and میلیون.
- Decimals with ممیزC1 — Write and read Persian decimals with ممیز, preserving place value, significant zeroes, units, and formal statistical conventions.
- Count, Mass, and Measure NounsA2 — How Persian distinguishes countable items from substances, builds measure and container phrases, and shifts a mass noun toward portions or varieties.
- Quantifier and Numeral SyntaxA2 — Build Persian quantified noun phrases with prenominal numbers, singular counted nouns, optional counting words, partitives, and meaning-based agreement.