[AC_in_Korea]

Can you explain to the students that if they speak Englsih too quickly in any other country, they may not be understood?
An idea came to me as I read your post -
Write two sentences on the board: I want some chicken. I chicken.
Explain to them what "I chicken" seems to mean. (They are saying I am a chicken, or I'm scared)
Maybe then they will see the importance of grammar, and it can be funny too.
I feel like these sentences aren't the best example, but hopefully my point comes across.
Please let us know what works for you.