Past deductions (bâyad... bâshad)

You walk into the kitchen, and it is an absolute disaster. To figure out who caused this, you will need to make some deductions.

To express logical probability in the past (saying someone must have done something), use باید (must) followed by the Present Perfect Subjunctive (ماضی التزامی).

Forming the Present Perfect Subjunctive

The formula is: Past Participle (Past Stem + ه) + Subjunctive of بودن (to be)

PronounAuxiliaryExample: رفتن (to go)Meaning
منباشمرفته باشمI have gone
توباشیرفته باشیYou have gone
او / آنباشدرفته باشدHe/She/It has gone
ماباشیمرفته باشیمWe have gone
شماباشیدرفته باشیدYou have gone
آن‌هاباشندرفته باشندThey have gone

Making Past Deductions

Place باید before the Present Perfect Subjunctive to mean must have [verb]-ed.

You can use this structure with any verb to follow the trail of clues.