In sentence A, “One” is the object of the sentence, and one of them is singular. There is no way to go. Some people find ways to argue that “none” is not singular, but “none is” acceptable, but I absolutely cannot see it. If “one” is singular, “zero” is also singular. In sentence B, we do arithmetic in the form of words, and “a third” is multiplication. If z.B. the number of new teachers is 999, then (1/3) x (999) – 333, which is still plural. Most languages have a usual word order like this: a) subject, verb, direct object. b) Subject, direct object, verb. c) The verb, the subject, the direct object. Other things like indirect objects and adverbs vary from language to language. The usual order of the words is quite mathematical and logical. When it comes to adjectives and adverbs, many people don`t seem to know that, in English: a) adjectives, including articles, usually continue their names, but the attached prepositional phrases usually follow them.

(A coral truck from the bottom of the ocean.) b) Adverbs, including adverbiale preposition phrases, usually follow their verbs. Exceptions are found where the adverb is highlighted. That`s how people “scream” who advance their adverbs all the time, all the time. You might as well write anything in UPPER CASE! If two options are presented as alternatives and not as a combination, with or not, a singular verb is appropriate, as it applies only to the first option: “The implementation of simplified solutions based on symptomatic causes or a single cause, if there are multiple causes of interaction, is very likely that failure and disappointment will end.” In #4, I don`t see how patchwork is a subject. The theme is federal and regional regulations. There is therefore a disagreement in the number/plurality. Sometimes collective nouns can be particularly confusing. If a single name implies that there are several people, the verb should be singular or plural?! The answer is simple. The verb must always correspond to written subjects (not implicit). You can also ask what is an example error verb object? The ability to find the right topic and verb will help you correct the errors of the subject verb agreement. The rule of thumb. A singular subject (she, Bill, auto) takes a singular verb (is, goes, shines), while a plural subject takes on a plural verb.