21d. Subjects joined with or, nor, either . . . or, or neither . . . nor
21dWith subjects joined with or or nor (or with either . . . or or neither . . . nor), make the verb agree with the part of the subject nearer to the verb.
The verb must be matched with the part of the subject closer to it: child has in the first sentence, managers were in the second.
note: If one part of the subject is singular and the other is plural, put the plural one last to avoid awkwardness.