How does the use of "each" affect subject-verb agreement?

The use of "each" indicates that the subject being referred to is treated as a singular individual within a group. This means that when "each" is the subject, it requires a singular verb to maintain proper subject-verb agreement. For example, in the sentence "Each of the students has completed their assignment," the verb "has" is singular, aligning with the singular implication of "each." This ensures clarity in communication, emphasizing that every individual in the group is being considered separately, which is why a singular verb is necessary.