The girl, a singular subject, following the rule of concord attracts a singular verb sings. However, the rule is broken in the subordinate clause that starts with "as if____________" because the expression is a subjunctive one and needs a subjunctive verB. Such verbs do not follow concord rule. They are a set of verb that refer to actions which are possibilities, wishes or hypothesis rather than facts or what will eventually happen.or example, the sentence I wish rich has the verb "were" in the subjunctive because ordinarily, the pronoun " \(\mathrm{l}\) " should go with "was/am" and not "were"