Fill the blank

Either you or I am responsible uses am as the verb agrees with the nearest subject I. This question tests subject-verb agreement knowledge. In either/or constructions the verb aligns with the closer noun. Had been and have been suggest past tense unsuitable for present responsibility. Are is incorrect for singular I. Understanding agreement rules ensures grammatical accuracy. This construction is common in formal writing or speech. Correct verb choice clarifies responsibility attribution. Knowing am is correct enhances sentence precision vital for professional or academic communication ensuring clarity in expressing accountability.