1. They each make a mistake. a. If we omit (erase) "each," the sentence is still correct: i. They make a mistake. 2. Each of them makeS a mistake. a. If we omit "of them," the sentence is still correct: i. Each makeS a mistake. 3. Tom and Mona each make a sacrifice. / Tom and Mona make a sacrifice each. a. As you can see, if we omit "each," the sentence is still correct. b. The word "each" in those sentences is called an APPOSITIVE. c. The appositive "each" refers to the subjects "Tom and Mona." d. You want to emphasize the fact that EACH of them (Tom and Mona) makeS a sacrifice. e. An appositive is extra information. It can be omitted, and the sentence is still grammatical. f. Here is another example of an appositive: The students ALL love their teacher. (If I omit "all," the sentence is still correct. I used "all" because I wanted to emphasize the fact that ALL -- not "some" -- of the students love their teacher.)

This is an example of one characteristic of English that can cause confusion. The “right” one is the one which is grammatically correct. English, unlike Chinese, has to conform to a certain sentence structure dictated by grammar rules. Since “they” is plural and “each” is singular, there is a problem in choosing the correct verb. The most customary way to resolve the problem is to word the sentence in a different way. To use either a singular subject (each) or a plural one (they) would solve the problem. They make sacrifices They all make sacrifices. Each of them makes a sacrifice.

They make a sacrifice.