As you can see, punctuation is very important, especially if the comma is missing from the following:
Let’s eat, Grandma
This is like an invitation to your grandmother saying something like “Hey Grandma, why don’t we have something to eat.”
HOWEVER…
If you don’t put the comma there, it becomes
Let’s eat Grandma
Here is sounds like you are telling your friends or someone else, “Hey, we should eat my grandmother.”
So, do you want to be cannibal? No?
Then don’t forgot the common.
Punctuation is important!
