Final answer:
The simple subject in the sentence is 'students'. It identifies the main noun in the sentence structure, while 'Some' is a quantifier and does not constitute the simple subject. Correct subject-verb agreement depends on whether the subject is singular or plural and if collective nouns act as a unit or as individuals.
Step-by-step explanation:
The simple subject in the sentence, "Some of the students are absent", is students. This is because 'students' is the main noun that is doing the action of being absent. The word 'Some' serves as a quantifier to specify which students are being talked about, but it is not the main noun in the sentence structure.
When dealing with subject-verb agreement, it is critical to identify the correct singular or plural verb that matches the subject of your sentence. Collective nouns may take singular or plural verbs depending on whether the group acts as a single unit or as individual members. For example, 'The band rehearses every Thursday' uses a singular verb because the band is acting as a single unit.