Expressing Causation
To state that one past event caused another—especially when diagnosing a problem or deducing an outcome—Farsi pairs the simple past باعث شد (caused) with که (that) and a subordinate clause in the past subjunctive.
The Past Subjunctive
Form the past subjunctive using the past participle (past stem + ه) followed by the present subjunctive of "to be" (باشم، باشی، باشد، باشیم، باشید، باشند).
For example, سوختن (to burn) becomes سوخته باشد. Paired with causative phrases and words of deduction like انگار (it seems) or احتمالاً (probably), it emphasizes a fully completed effect.
| It seems a spark in the transformer caused the whole system to burn. | انگار یک جرقه در ترانسفورماتور باعث شد که کل سیستم سوخته باشد.engâr yek jaraghe dar transformâtor bâ'es shod ke kol sistem sukhte bâshad. |
| His negligence probably caused the fuse to blow. | احتمالاً سهلانگاری او باعث شد که فیوز پریده باشد.ehtemâlan sahl-engâri u bâ'es shod ke fiyuz paride bâshad. |
When the subject of the subordinate clause changes (like an overload causing a blackout), the past subjunctive verb simply agrees with the new subject.
| The overload probably caused one of the worst blackouts to happen. | احتمالاً اضافهبار باعث شد که یکی از بدترین خاموشیها اتفاق افتاده باشد.ehtemâlan ezâfe-bâr bâ'es shod ke yeki az badtarin khâmushi-hâ ettefâq oftâde bâshad. |
| It seems that the short circuit caused the voltage to drop. | به نظر میرسد که اتصالی باعث شد که ولتاژ افت کرده باشد.be nazar mi-resad ke ettesâli bâ'es shod ke voltâzh oft karde bâshad. |
Compound Verbs
With compound verbs like از کار انداختن (to disable), apply the past subjunctive rule only to the verbal component. The non-verbal part remains unchanged.
| Perhaps the storm caused the pylon to disable the power grid. | شاید طوفان باعث شد که دکل شبکهی برق را از کار انداخته باشد.shâyad tufân bâ'es shod ke dokol shabake-ye barq râ az kâr andâkhte bâshad |
| One of the worst short circuits probably caused the fuse to disable the system. | احتمالاً یکی از بدترین اتصالیها باعث شد که فیوز سیستم را از کار انداخته باشد.ehtemâlan yeki az badtarin ettesâli-hâ bâ'es shod ke fyuz sistem râ az kâr andâkhte bâshad. |