I totally agree with giving clear instructions. Sometimes they are just very simple minded.

I remembered during my kindergarten teaching days, I told the students to let me know when they want to head to the bathroom.

So in Malay it was translated to
"Cikgu, saya nak pergi tandas"

Some of the time the kids decided to remember the keywords,

Cikgu, saya, tandas

And they will come up with short quotes like

"Cikgu tandas"

"Cikgu, saya tandas"