Persian has no single obligatory equivalent of English a/an. To talk about one new or indefinite referent, speakers may put یک before the noun, add indefinite ـی to the end of the noun phrase, use both, or leave the noun bare. The best choice depends on whether “one” matters, whether the referent is being introduced as an individual, and whether the style is conversational or narrative.
The practical contrast is this: یک first selects one item and often introduces it; ـی presents an indefinite member of a class. Their meanings overlap, but their position and discourse flavor differ. This decision guide chooses among them; Indefiniteness with یک and ی gives the full structural account.
The Decision Tree
- Does “exactly one, not two” matter? Use یک + singular noun.
- Are you simply introducing one countable participant in ordinary speech? یک + noun is the easiest neutral choice; یه + noun is normal (informal, regional: Tehran).
- Are you presenting “some member of the class,” especially in written narrative or after an adjective? Use final ـی: مردی، خانهای، کتاب خوبی.
- Do you want a salient “a certain / this particular sort of” effect? یک ... ـی is possible, especially in conversation and storytelling.
- Is the noun a nonspecific object and number does not matter? A bare noun may be best: کتاب خریدم “I bought a book/books; I did some book-buying.”
| Choice | What it foregrounds | Typical register |
|---|---|---|
| یک بلیت | one ticket or one newly introduced ticket | all modern registers |
| بلیتی | an indefinite ticket, one member of the class | neutral; especially comfortable in writing |
| یک بلیت ارزانی | a certain/salient cheap ticket | marked conversational or narrative |
| بلیت خریدم | ticket-buying, identity and number backgrounded | neutral |
Choose یک When Counting Matters
When یک contrasts with another number or appears with words such as فقط “only,” its numeral meaning is central. The following noun stays singular. Stress may also make the numeral contrast clear in speech.
فقط یک اتاق تا آخر هفته خالی مانده است.
faghat yek otâgh tâ âkhar-e hafte khâli mânde ast.
Only one room remains available through the weekend. (neutral; exact number matters)
برای جلسه یک صندلی دیگر لازم داریم، نه دو تا.
barâ-ye jalase yek sandali-ye digar lâzem dârim, na do tâ.
We need one more chair for the meeting, not two. (neutral; explicit count contrast)
The same یک can introduce a new person or thing without strong numerical emphasis. In careful standard Persian it remains یک. Everyday Tehran speech normally reduces article-like یک to یه.
یک بسته برای شما روی میز پذیرش گذاشتهاند.
yek baste barâ-ye shomâ ru-ye miz-e pazirosh gozâshte-and.
Someone has left a package for you on the reception desk. (careful standard; new referent)
یه آقایی پایین منتظرته.
ye âghâ-yi pâ'in montazer-ete.
There's a gentleman downstairs waiting for you. (informal, regional: Tehran; یک ... ـی introduces a salient person)
Choose Final ـی for an Indefinite Member
Indefinite ـی attaches at the right edge of the nominal expression. It produces مردی “a man,” خانهای “a house,” and پیشنهاد خوبی “a good suggestion.” In the last example, ezâfe links پیشنهاد to خوب, and ـی closes the whole modified phrase.
زنی از انتهای سالن اسم مرا صدا زد.
zani az entehâ-ye sâlon esm-e marâ sedâ zad.
A woman called my name from the far end of the hall. (neutral written narrative; new participant)
خانهای نزدیک ایستگاه پیدا کردهایم.
khâne-i nazdik-e istgâh peydâ karde-im.
We have found a house near the station. (neutral standard; indefinite member)
برای مشکل برق راهحل سادهای پیدا شد.
barâ-ye moshkel-e bargh râh-hall-e sâde-i peydâ shod.
A simple solution was found for the electrical problem. (formal-neutral; suffix after the adjective)
Written stories readily use ـی to bring a participant onstage. Conversation also uses it, but casual speech often prefers یه, or combines یه ... ـی when the new referent is especially salient. This is a tendency, not an opposition between “written ـی” and “spoken یک.” Both markers occur across registers.
When Either Form Works
Compare two ways to answer “What happened?”:
جلوی ساختمان یک تاکسی ایستاده بود.
jelow-ye sâkhtemân yek tâksi istâde bud.
A taxi was parked in front of the building. (neutral; one vehicle is introduced)
جلوی ساختمان تاکسیای ایستاده بود که چراغش خاموش بود.
jelow-ye sâkhtemân tâksi-i istâde bud ke cherâgh-ash khâmush bud.
A taxi whose light was off was parked in front of the building. (written narrative; an indefinite member is developed)
The outside situation may be identical. یک تاکسی makes one taxi an accessible discourse participant. تاکسیای classifies it as an indefinite taxi and flows naturally into the relative clause. Neither form is inherently “more definite.”
The combined pattern یک ... ـی is also grammatical, but it is not a required double article. It commonly adds salience, surprise, evaluation, or “a certain” flavor.
دیشب یک صدای عجیبی از راهرو شنیدم.
dishab yek sedâ-ye ajibi az râhro shenidam.
Last night I heard this strange sound from the corridor. (conversational; salient indefinite)
Two Ambiguous Contexts, Resolved Aloud
یک چای: article or numeral?
At a café, یک چای میخواهم normally means one serving of tea. If the server asks whether the order is one tea or two, stress یک; if the count is irrelevant and you only want the substance, choose bare چای.
یک چای میخواهم؛ دوستم قهوه سفارش میدهد.
yek chây mi-khâham; dustam ghahve sefâresh mi-dahad.
I'd like one tea; my friend is ordering coffee. (neutral; one serving is understood)
کتاب خریدم: one book or book-buying?
Bare کتاب خریدم leaves number and identity in the background. If the next sentence tracks one particular book, introduce it with یک کتاب or کتابی. If the point is simply what kind of shopping you did, keep the object bare.
برای بچهها کتاب خریدم و بعد رفتم سراغ لباس.
barâ-ye bachche-hâ ketâb kharidam va ba'd raftam sorâgh-e lebâs.
I bought books for the children and then went to look for clothes. (neutral; number-neutral shopping activity)
Specificity is a separate decision. A particular indefinite direct object can later take را, as in کتابی را که گفتی پیدا کردم. Do not choose between یک and ـی by using را as a supposed definiteness test; the next را or No را? guide handles that choice.
Common Mistakes
1. Translating every English a/an with یک
⚠️ من برای سفر یک لباس خریدم.
man barâ-ye safar yek lebâs kharidam.
Grammatical, but it selects one garment; do not use it for the intended number-neutral meaning ‘I bought clothes for the trip.’
✅ من برای سفر لباس خریدم.
man barâ-ye safar lebâs kharidam.
I bought clothes for the trip.
2. Putting indefinite ـی on the noun before its adjective
❌ کتابی جالبی کنار تخت بود.
Incorrect — indefinite ـی is not repeated on both the noun and its adjective.
✅ کتاب جالبی کنار تخت مهمان بود.
ketâb-e jâlebi kenâr-e takht-e mehmân bud.
An interesting book was beside the guest bed.
3. Treating یک ... ـی as obligatory
⚠️ هر بار که اسم تازهای میآید، باید هم یک بگذاریم و هم ی.
har bâr ke esm-e tâze-i mi-âyad, bâyad ham yek be-gozârim va ham i.
The sentence is grammatical, but the rule is false: the combined pattern is marked for salience, not required for every new noun.
✅ امروز همکار تازهای به گروه ما پیوست.
emruz hamkâr-e tâze-i be goruh-e mâ peyvast.
A new colleague joined our team today.
4. Using the plural after numeral یک
❌ یک پیامها برایت فرستادم.
Incorrect — the noun after numeral یک is singular.
✅ یک پیام کوتاه برایت فرستادم.
yek payâm-e kutâh barây-at ferestâdam.
I sent you one short message.
Key Takeaways
Final checklist:
- Exact count “one”? Choose یک.
- Ordinary spoken introduction? Choose یک; یه is informal Tehran speech.
- Indefinite member or written narrative introduction? Choose final ـی.
- “A certain / this striking X”? یک ... ـی may fit.
- Number-neutral nonspecific object? Consider no marker.
- Specific direct object? Make the separate را decision after building the noun phrase.
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Start learning Farsi →Related Topics
- Indefiniteness with یک and یA1 — How Persian introduces one or an indefinite referent with یک, suffix ـی, both together, or no article-like marking at all.
- Indefinite ی on NounsA2 — How the unstressed indefinite clitic ـی selects an unspecified member or amount, changes shape after vowels, and scopes over modified noun phrases.
- Bare Nouns and Basic ReferenceA1 — How an unmarked Persian noun can name a kind, introduce nonspecific material, or identify a contextually familiar referent.
- Specificity across یک، ی، and راB2 — Understand how Persian یک, indefinite ی, bare nouns, discourse, and object marker را divide indefiniteness from specificity.
- را or No را?A2 — Choose object marker را according to grammatical role, identifiability, specificity, animacy, discourse status, and register.