"Bedsheets are not toys."
Translation:Seprai bukan mainan.
'mainan' is a noun.
base word = 'main' (verb)
base word + an = noun
'bukan' is used to negate nouns.
Here is a Tinycards decks with examples (negation) :
No need to do the lessons there, just flip through the cards of the deck to see the examples.