I would like to offer my two cents,
There is a very easy rule for "each" and "every" - they are always grammatically singular! Even though the idea of them is plural, we always use the singular verb.
Each student has a book.
Every teacher is extremely helpful.Even though we mean all of the students and all of the teachers, the words "each" and "every" refer to each individual student and each individual teacher. So, our verb is matching that idea of every single student and teacher.
Be careful with "each of" because the noun that will follow will be plural, and it's very tempting to match the verb to the plural noun.
Each of the students has a book.The three apples each WERENow here, "each" is used as an adverb. Our subject is "apples," and the adverb "each" tells us that we want to think about the apples individually.
The three apples were each $1.
Without "each," I think that it cost $1 to buy all three apples. But when I add "each," I know that individually the three apples were $1 - altogether it cost $3 for the three apples.
Please help with Kudos if the post has helped...