Today’s lesson is tricky. Maybe even boring! The problem is with the difference between “each,” “every,” and “all.” These words can appear when you refer to a group of things, including things in a list. This tempts you to use a plural verb, especially if you mention the group itself. But “each” refers to the items one at a time, and though “every” refers to them as individual parts of the whole group, they are both singulars, so they get singular verbs.
If you want a plural verb with a group, use “all” or “some.” (If it’s not a group, “all” can be singular: All of the cake is eaten!)
So:
Each of the computers is shut down. (Not Each of the computers are shut down.)
Every one of the computers is shut down. (Not …are shut down)
All of the computers are shut down.
Let’s try a trickier one:
Opening the file, reading the file, and deleting the file—each is a separate module.
Each of opening the file, reading the file, and deleting the file is a separate module.
Every one of opening the file, reading the file, and deleting the file is a separate module.
All of opening the file, reading the file, and deleting the file are separate modules.
Just remember, “each” and “every” are singulars, and “all” is a plural when you refer to a group.