Questions & Answers about اینکه جد ما به این شهر مهاجرت کرد حقیقت است.
How does in-ke act as the subject of this sentence?
The phrase in-ke literally means this that, but translates to the fact that. It packages the entire action jadd-e mā be in shahr mohājerat kard (our ancestor migrated to this city) into a single noun clause. This whole clause acts as the main subject for the final verb ast (is).
Why is the main verb ast all the way at the end, separated from the beginning of the sentence?
Farsi typically follows a Subject-Object-Verb word order. Since the entire long in-ke clause acts as the subject, it takes up the first half of the sentence. Then comes the complement haqiqat (truth) and finally the main verb ast (is).
Why are there two different tenses used in this sentence?
The migration is a completed action in the past, so the simple past tense mohājerat kard is used inside the in-ke clause. However, the statement about it being a truth applies to the present, which is why the sentence ends with the present tense ast.
Why do we use the preposition be before in shahr?
The preposition be means to. Just like in English, the compound verb mohājerat kardan (to migrate) pairs with this preposition to show the destination of the movement.