The past stem in Persian is simply formed by removing “an” from the end of the infinitive. Then, personal endings are added to this stem. For example, for the verb ‘to laugh,’ remove ‘an’ from the infinitive[tag resources paststem_01] خندیدن [/tag] xandidan to make [tag resources paststem_02]خندید [/tag] xandid “He laughed,” and then add the first person singular ending[tag resources paststem_03] م [/tag]to make[tag resources paststem_04] خندیدم [/tag] xandidam
“I laughed.” The past tense third-person singular does not have an ending. Hence, “He laughed” is the same as the past stem[tag resources paststem_05] خندید[/tag] xandid.

The personal endings in the past tense are as follows:

Unlike in English, in Persian, when in a single sentence or two or more dependent clauses in the past tense more than one verb is incorporated, the first verb sets the tense (in the past) and the rest of the verbs are invariably in the present tense. For example:

[tag resources paststem_11]متوجّه شدم که او در خانه نیست[/tag]
motevajjeh šodam ke u dar xāne nist
“I realized that he/she was not at home.”

[tag resources paststem_12]به من گفت که خسته است[/tag]
be man goft ke xaste ast
“S/he told me that s/he was tired.”

[tag resources paststem_13]به من گفت که او را ندیده است[/tag]
be man goft ke u rā nadide ast
“S/he told me that s/he had not seen him/her.”

[tag resources paststem_14]باید می‌فهمیدم که او در آبادان خوشحال است[/tag]
bāyad mi fahmidam ke u dar ābādān xošhāl ast
“I should have realized that s/he was happy in Abadan.”