@e target selector does not work with some commands I think would make sense to be possible. This includes /give and /clear, and I will use those as examples. There are other commands which could benefit from @e, although I will need to look up the format to test them.

What I expected to happen was...:
When using /give and /clear with an entity target selector (@e), I would be able to respectively give the entity an item and clear the entities inventory or specific items.

What actually happened was...:
For each entity, you receive the message "The player cannot be found," meaning that the commands do not support entities. This is a lack of control which @e would benefit to include.

Steps to Reproduce:
1. Have commands enabled and be within 5 blocks of a zombie, then copy and paste either of these commands into chat:

/give @e[type=Zombie,r=5,c=-1] minecraft:stone_sword

/clear @e[type=Zombie,r=5,c=-1] minecraft:stone_sword 0 0

2. Instead of the zombie respectively being given a stone block or returning if it has a stone block, you will receive the message: That player cannot be found