When do we use det v. den?
It depends on the gender of the noun you're referring to, or 'det' if you're not referring to something.
Example: Instead of "Denne boken er bra. De leser boken", you would say "Denne boken er bra. De leser den".
Could this also mean 'They read that' ?
Why have they used det.. Shouldn't it be den?