Learn Farsi: کاش این وصلت برای هر دو خانواده شاد باشد. - I hope this union is joyful for both families.

kâsh (or ey kâsh) can mean either, depending on the verb tense that follows it. Because it is paired here with the present subjunctive, it expresses a realistic, possible hope for the future ("I hope it is joyful"). If it were paired with a past tense verb, it would express an unrealized wish ("I wish it were joyful").

Why do we use the subjunctive bâshad instead of the normal present tense ast?

The word kâsh requires the subjunctive mood because it introduces a desire or hope rather than a stated fact. bâshad is the present subjunctive form of budan (to be).

Why is khânevâdeh (family) singular when the sentence translates to "both families"?

As a quick refresher: in Farsi, nouns that follow numbers or number-based quantity phrases like har do (both / literally "every two") always remain in their singular form. You never add a plural suffix after a number.

Does vaslat mean "union" in any context, like a labor union or political union?

No, vaslat specifically refers to a marriage or matrimonial union that ties two families together. For a labor union or a political alliance, you would use a completely different word, like ettehâdiyeh.

Would a native speaker actually say bâshad in a real conversation?