Breakdown of يجب أن يخضع البحار للقبطان، وإلا سيشنقه.
الal
the
هhu
his / him (object) / it (dummy pronoun after لأن)
لli
for, to (attached)
سsa
will (future prefix)
Questions & Answers about يجب أن يخضع البحار للقبطان، وإلا سيشنقه.
How is وإلا formed, and does it change the mood of the verb in سيشنقه?
The word وإلا is a contraction of و (and), the conditional إن (if), and لا (not). While إن normally puts the following verb in the jussive (majzum) mood, the consequence here is introduced by the future prefix سـ in سيشنقه. This prefix shields the verb from the conditional particle, so it stays in the regular indicative mood.
Why do we use the preposition لـ in للقبطان instead of just a direct object?
The verb خضع (to submit or yield) requires the preposition لـ to indicate who or what is being submitted to. It does not take a direct object directly, so we must say he submits to the captain.
What causes the verb يخضع to be in the subjunctive mood here?
The verb follows أن (that). The common construction يجب أن (it is necessary that / must) always triggers the subjunctive (mansub) mood in the present tense verb that follows it, which is why it would end with a fatha if fully vocalized.
How do we know who is the subject and who is the object in سيشنقه?