The Persian past stem is completely predictable from the infinitive: remove final ن. Thus خوردن → خورد and نوشتن → نوشت. What is often hard is predicting that past stem from the present stem. The pairs خور / خورد “eat,” نویس / نوشت “write,” and بین / دید “see” show three different historical relationships.
English learners should therefore avoid thinking of the past as an ending added to a single unchanging verb base. A Persian verb has two lexical stems. Recurring sound patterns make many pairs easier to remember, but they do not replace learning the infinitive and present stem together.
The one fully reliable operation
Start with the dictionary infinitive and delete only its final ن. Do not remove the preceding د or ت; that consonant belongs to the past stem.
| Infinitive | Past stem | Third-person singular past |
|---|---|---|
| خوردن | خورد | خورد |
| رسیدن | رسید | رسید |
| ساختن | ساخت | ساخت |
| گفتن | گفت | گفت |
دیشب فقط کمی سوپ خوردم.
dishab faqat kami sup khordam.
I ate only a little soup last night. (neutral standard; خوردن → خورد)
بسته امروز سالم رسید.
baste emruz sâlem resid.
The package arrived intact today. (neutral standard; رسیدن → رسید)
This infinitive rule has no lexical exceptions in ordinary modern Persian. Apparent difficulty begins only when a learner tries to move directly between the present and past stems.
Past stems ending in د
Many native verbs have a past stem ending in د. One transparent family has a present stem that is also visible before that consonant:
| Present stem | Past stem | Infinitive | Meaning |
|---|---|---|---|
| خور | خورد | خوردن | eat |
| خوان | خواند | خواندن | read |
| مان | ماند | ماندن | remain |
Another large set has ـید in the past stem, often beside a shorter present stem: رس / رسید، پرس / پرسید، خند / خندید، خر / خرید. This family is useful for recognition, but ـید is not a suffix that learners can freely add to any present stem.
تا نیمهشب در دفتر ماندیم.
tâ nime-shab dar daftar mândim.
We stayed at the office until midnight. (neutral standard; مان / ماند)
از مسئول پذیرش دربارهی ساعت کار پرسیدم.
az mas'ul-e pazirish darbâre-ye sâ'at-e kâr porsidam.
I asked the receptionist about the opening hours. (neutral standard; پرس / پرسید)
همه به شوخی او خندیدند.
hame be shukhi-ye u khandidand.
Everyone laughed at his joke. (neutral standard; خند / خندید)
Past stems ending in ت and recurring sound correspondences
Past ت often occurs together with a change in the rest of the stem. These correspondences reflect the history of Persian, not a single productive classroom rule.
| Recurring family | Present / past | Infinitive | Meaning |
|---|---|---|---|
| ز / خت | ساز / ساخت | ساختن | make, build |
| ز / خت | سوز / سوخت | سوختن | burn |
| ش / خت | فروش / فروخت | فروختن | sell |
| نویس / نوشت | نویس / نوشت | نوشتن | write |
| بند / بست | بند / بست | بستن | close, tie |
The table is a memory aid, not an algorithm. From ساز you can learn to expect ساخت, but a new stem ending in ز does not automatically form its past in خت.
آنها پل تازه را در دو سال ساختند.
ân-hâ pol-e tâze râ dar do sâl sâkhtand.
They built the new bridge in two years. (neutral standard; ساز / ساخت)
فروشگاه همهی بلیتها را یکروزه فروخت.
forushgâh hame-ye bilit-hâ râ yek-ruze forukht.
The shop sold all the tickets in one day. (neutral standard; فروش / فروخت)
قبل از رفتن همهی پنجرهها را بستم.
qabl az raftan hame-ye panjare-hâ râ bastam.
I closed all the windows before leaving. (neutral standard; بند / بست)
The causative ـاندن family
A recognizable causative family has present stem ـان and past stem ـاند; the infinitive ends in ـاندن. It often means “cause someone or something to enter the base verb's state”: خوابیدن “sleep” beside خواباندن “put to sleep,” and رسیدن “arrive” beside رساندن “deliver, cause to reach.”
| Causative infinitive | Present stem | Past stem | Meaning |
|---|---|---|---|
| خواباندن | خوابان | خواباند | put to sleep; lay down |
| ترساندن | ترسان | ترساند | frighten |
| رساندن | رسان | رساند | deliver; bring to |
تاکسی ما را تا ورودی هتل رساند.
tâksi mâ râ tâ vorudi-ye hotel rasând.
The taxi took us as far as the hotel entrance. (neutral standard; causative رساندن)
The pattern is morphologically clear, but it is not freely available for every verb in present-day speech. Persian often chooses a lexical verb or a compound with کردن instead. The full syntax and productivity of this pattern are covered under Causatives in ـاندن.
Lexical pairs must be learned
Some of the most frequent verbs show large differences between their two stems: کن / کرد “do,” بین / دید “see,” رو / رفت “go,” گو / گفت “say,” and آی / آمد “come.” No sound rule will safely derive one member from the other.
دیروز همکار قدیمیام را در مترو دیدم.
diruz hamkâr-e qadimi-am râ dar metro didam.
Yesterday I saw my former colleague on the metro. (neutral standard; بین / دید)
برای حل مشکل هر کاری کردیم.
barâ-ye hall-e moshkel har kâri kardim.
We did everything we could to solve the problem. (neutral standard; کن / کرد)
Common Mistakes
1. Removing too much from the infinitive
❌ من صبحانه خورم.
as a simple-past form rather than a subjunctive or literary present form
Incorrect as a simple past — deleting دن from خوردن produces the present stem خور, not the past stem.
✅ من صبحانه را در راه خوردم.
man sobhâne râ dar râh khordam.
I ate breakfast on the way.
2. Inventing an ـید past for every verb
❌ او نامه را نویسید.
Incorrect — نوشتن has the lexical past stem نوشت, not نویسید.
✅ او نشانی تازه را پشت پاکت نوشت.
u neshâni-ye tâze râ posht-e pâkat nevesht.
She wrote the new address on the back of the envelope.
3. Using the present stem in a simple past
❌ ما ساعت نه به خانه رومیم.
Incorrect — the simple past of رفتن uses past stem رفت.
✅ ما ساعت نه به خانه رفتیم.
mâ sâ'at-e noh be khâne raftim.
We went home at nine.
4. Treating a historical pattern as freely productive
❌ تعمیرکار دستگاه را سازید.
Incorrect — ساختن has past stem ساخت; the ز / خت correspondence is lexical.
✅ نجار میز را همان روز ساخت.
najjâr miz râ hamân ruz sâkht.
The carpenter made the table that same day.
Key Takeaways
- Delete final ن from an infinitive to obtain its past stem.
- Many past stems end in د or ت, but their relationship to the present stem is lexical.
- Families such as رس / رسید and ساز / ساخت help memory; they do not license new forms automatically.
- Causatives in ـاندن transparently pair present ـان with past ـاند.
- Learn high-frequency stem pairs as vocabulary, then add the regular personal endings.
Now practice Farsi
Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.
Start learning Farsi →Related Topics
- The Infinitive and Past StemA1 — Recognize Persian infinitives, recover the fully predictable past stem, and use both forms correctly when learning and looking up verbs.
- The Present StemA1 — Learn why Persian present stems must be stored with each verb, recognize common alternations, and use the stem in present-system forms.
- How a Persian Verb Is BuiltA1 — See how Persian combines two stems with prefixes, personal endings, participles, and light verbs to build its verbal system.
- Irregular Simple-Past ParadigmsA2 — Conjugate بودن، داشتن، رفتن، آمدن, and گفتن in the simple past, including zero-marked third person, negatives, and compound predicates.
- Causative in اندن and انیدنA2 — Recognize Persian morphological causatives in ـاندن and ـانیدن, their derived stems and added arguments, and the lexical limits on forming new causatives.