Questions & Answers about من شک دارم که او قاتل بوده باشد.
Why does this sentence use bude bâshad instead of the simple past bud?
Because you are expressing doubt about a past event. In Farsi, when you use a phrase like shak dâram (I doubt) followed by ke (that), the verb in the second part of the sentence must be in the subjunctive mood. Since the doubt is about something in the past (that he was the murderer), we use the Present Perfect Subjunctive rather than the simple past.
How exactly is the verb form bude bâshad built?
It is the Present Perfect Subjunctive of budan (to be). You form it by taking the past participle bude (been) and adding the present subjunctive forms of to be, which in this case for u (he/she) is bâshad. So, bude + bâshad literally behaves like may have been, perfectly fitting the feeling of doubt.
If I want to say I doubt he is the murderer (present tense), how would the verb change?
You would change the second verb to the present subjunctive. The present subjunctive of budan for he/she is bâshad. So the sentence would simply be: man shak dâram ke u ghâtel bâshad.
Can I leave out ke (that) in everyday speech, like we do in English?
Yes! Just like in English where you can say I doubt he was the murderer, in conversational Farsi it is very common to drop ke. In everyday spoken Farsi, you will often hear man shak dâram u ghâtel bude bâshe (also noting the spoken form instead of the formal ).