there's the rule that if subjects are joined by or/nor the plural subject is placed next to the verb - English - Subject-Verb Agreement

Question

there's the rule that if subjects are joined by or/nor the
plural subject is placed next to the verb and the verb takes plural
form why

Amrita Hazra · Accepted Answer

It is just a convention It cannot be
questioned It is one of the thousands of rules followed in English
grammar It does not have any reason as stated

there's the rule that if subjects are joined by or/nor the plural subject is placed next to the verb and the verb takes plural form. why