As we saw in the discussion regarding the Present Subjunctive, under normal circumstances the subjunctive has to do with elements of doubt, tentativeness, uncertainty, and vagueness. Also see the Perfect Subjunctive for additional explanation.

Unlike English, in Persian the past subjunctive is divided into two categories: simple past, and past continuous, depending on the tense of the primary verb.

There are two sets of construction for the past subjunctive:

When the modal verbs باید bāyad ‘must, should’ and شاید šāyad ‘perhaps, maybe,’ and the conjunction اگر agar ‘if’ are used, the verb used is a conjugated past progressive. Compare the following pairs:

[tag resources pastsub_01]باید به آنجا بروم[/tag]
bāyad be ānjā beravam
“I have to go there.”

[tag resources pastsub_02]باید به آنجا می رفتم[/tag]
bāyad be ānjā miraftam
“I had to go there.”

[tag resources pastsub_03]شاید به آنجا بروم[/tag]
šāyad be ānjā beravam
“Maybe I go there, I may go there.”

[tag resources pastsub_04]شاید به آنجا می رفتم[/tag]
šāyad be ānjā miraftam
“Perhaps I would have gone there.”

Notice the difference between Persian and English in the second sentence, past tense.

In the case of اگر both primary and secondary verbs correspond in tense:

[tag resources pastsub_05]اگر به آنجا بروی، او هم می آید[/tag]
agar be ānjā beravi, u ham mi āyad
“If you go there, he/she would go too.”

[tag resources pastsub_06]اگر به آنجا می رفتی، او هم می آمد[/tag]
agar be ānjā mirafti, u ham mi āmad
“If you had gone there, he/she would have gone too.”

Notice the difference between Persian and English in the second sentence, past tense.

Although historically the word بایست bāyest is the past stem as well as the third person singular past tense of the verb بایستن bāyestan ‘to be imperative,’ and باید bāyad is the third person singular in the present tense, in New Persian,[tag resources pastsub_11]باید[/tag]bāyad ,[tag resources pastsub_10]بایست[/tag]bāyest,[tag resources pastsub_09]می باید[/tag]mibāyad,[tag resources pastsub_08]می بایست[/tag]mibāyest,[tag resources pastsub_07]بایستی[/tag]bāyesti,and[tag resources pastsub_12] می بایستی [/tag]mibāyestiall mean ‘must, it is mandatory.’ In the construction of any tense in the subjunctive, these words stay constant and always remain in the third person singular:

Present:

[tag resources pastsub_13]باید بروم، بایست بروم، می باید بروم، می بایست بروم، بایستی بروم، می بایستی بروم[/tag]
bāyad beravam, bāyest beravam, mibāyad beravam, mibāyest beravam, mibāyesti beravam
“I must go, have to go, am going to have to go.”

Past:

[tag resources pastsub_14]باید می رفتم، بایست می رفتم، می باید می رفتم، می بایست می رفتم، بایستی می رفتم، می بایستی می رفتم[/tag]
bāyad miraftam, bāyest miraftam, mibāyad miraftam, bāyesti miraftam, mibāyesti miraftam
“I had to go, I was bound to go; I should have gone.”

With all other primary verbs, the subjunctive is invariably in the present tense, while the primary verb sets the tense—simple past, past progressive, past perfect, etc. The difference between the simple and continuous past is in their duration; and, of course, the continuous takes the می prefix. In the following example, compare the present and past tense:

[tag resources pastsub_15]می خواهم به آنجا بروم[/tag]
mi xāham be ānjā beravam
“I want to go there.”

[tag resources pastsub_16]خواستم به آنجا بروم[/tag]
mi xāstam be ānjā beravam
“I wanted/wished to go there.”

[tag resources pastsub_17]می خواستم به آنجا بروم[/tag]
mi xāstam be ānjā beravam
“I wanted (as in “was determined, it was my wish”) to go there.”

[tag resources pastsub_18]همیشه خواسته ام به آنجا بروم[/tag]
hamiše xāste am be ānjā beravam
“I have always wanted to go there.”

Now do the same in the following example:

[tag resources pastsub_19]می توانی امروز آن را ببینی[/tag]
mi tavāni emruz ān rā bebini
“You can/may see it today.”

[tag resources pastsub_20]دیروز می توانستی آن را ببینی[/tag]
diruz mi tavānesti ān rā bebini
“You could see it yesterday.”

[tag resources pastsub_21]دیروز توانستی آن را ببینی؟[/tag]
diruz tavānesti ān rā bebini?
“Were you able to see it yesterday?”

[tag resources pastsub_22]می توانی فردا آن را ببینی[/tag]
mi tavāni fardā ān rā bebini
“You can/may see it tomorrow.”

[tag resources pastsub_23]می توانستی دیروز آن را دیده باشی[/tag]
mi tavānesti diruz ān rā bāši
“You could have seen it yesterday.”

To understand the difference between the simple past and past progressive, or continuous, subjunctive in Persian, compare the English translations of the following sentences:

[tag resources pastsub_24]رفتم (که) او را ببینم[/tag]
raftam (ke) u rā bebinam
“I went to see him/her.”

[tag resources pastsub_25]می رفتم (که) او را ببینم[/tag]
mi raftam (ke) u rā bebinam
“I was going to see him/her; I used to go to see him/her.”

[tag resources pastsub_26]خواستم (که) او را ببینم[/tag]
xāstam (ke) u rā bebinam
“I asked to see him/her.”

[tag resources pastsub_27]می خواستم (که) او را ببینم[/tag]
mi xāstam (ke) u rā bebinam
“I wanted/was willing to see him/her, it was my (strong) wish to see him/her.”

The English “you could have seen it…” is discussed in the section on Perfect Subjunctive.

Here are some examples to look at. Notice the different tenses of the main verb:

[tag resources pastsub_28]میل داشتم او هم بیاید[/tag]
meyl dāštam u ham biyāyad
“I really liked him/her to come too.”

[tag resources pastsub_29]فکر می کردم او هم آنجا باشد[/tag]
fekr mi kardam u ham ānjā bāšad
“I thought he/she would be there too.”

[tag resources pastsub_30]می خواستی این را هم بشنوی؟[/tag]
mi xāsti in rā ham bešnavi?
“Did you want to hear/listen to this one too?”

[tag resources pastsub_31]خواستند (که) من هم چیزی بگویم[/tag]
xāstand (ke) man ham cizi beguyam
“They asked me to say something too, they wanted me to say something too.”

[tag resources pastsub_32]دنبال کسی می گشت که فارسی بلد باشد[/tag]
donbāl-e kasi mi gašt ke fārsi balad bāšad
“She/he was looking for someone who knew English.”

[tag resources pastsub_33]دنبال کسی گشت که فارسی بلد باشد[/tag]
donbāl-e kasi gašt ke fārsi balad bāšad
“She/he looked for someone who would/might know English.”

[tag resources pastsub_34]آنجا چیزی نداشتند که به کار او بخورد[/tag]
ānjā cizi nadāštand ke be kār-e u bexorad
“They did not have anything there that would/could be of any use to him.”

[tag resources pastsub_35]سعی کردم صدایش را بشنوم[/tag]
sa’y kardam sedāyaš rā bešnavam
“I tried to hear his/her voice.”

[tag resources pastsub_36]کوشش کردند که شما را پیدا کنند[/tag]
kušeš kardan ke šomā rā peydā konand
“They tried to find you.”

[tag resources pastsub_37] آیا) مجبور بودی او را ببینی؟)[/tag]
(āyā) majbur budi u rā bebini?
“Did you (really) have to see her/him?”

[tag resources pastsub_38]ناچار بود زود تر برود[/tag]
nācār bud zud tar beravad
“He had to leave soon(er).”

[tag resources pastsub_39]آمده بودم (که) پدرم را ببینم[/tag]
āmade budam (ke) pedaram rā bebinam
“I was there to see my father.”
[tag resources pastsub_40]مصمّم بود (که) بیاید[/tag]
mosammam bud (ke) biyāyad
“He was determined to come.”

[tag resources pastsub_41]مصمّم شده بود (که) بیاید[/tag]
mosammam šode bud (ke) biyāyad
“He had been determined to come.”