15. When is a verb put into the nominative case?
A verb is put into the nominative case if it is not preceded by a subjunctive or jussive preposition. For example: یَنزِلُ المَطَرُ (The rain is falling.)
16. Are vowel signs present at the end of a weak verb?
If the last letter of weak verb is an alif, the dummah is erased in the nominative case and the fathah is erased in the subjunctive case. But, if the last letter of the weak verb is either a wāw or a yā', the dummah is erased in the nominative case because of the difficulty of pronouncing it.