These are some useful sentences that you can use to warn your student:
“Make sure you don’t touch/ knock over the OHP/ fish tank”
“Don’t touch the wall too hard (or you could go through!)”
“(Be careful.) There’s a sharp corner here”
“Remember that someone hurt themselves on this/ in this game last week”
“If you push, someone will get hurt”
“You’ll hurt yourself if you do that again”
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