$\textrm{1. (-) They aren't cooking in the kitchen now}$
$\textrm{ (?) Are they cooking in the kitchen now?}$
$\textrm{2. (-) There aren't 4 pens on the table}$
$\textrm{ (?) Are there 4 pens on the table}$
$\textrm{3. (-) My father doesn't watch TV every day}$
$\textrm{ (?) Does your father watch TV every day?}$
$\textrm{4. (-) She isn't having dinner at the moment}$
$\textrm{ (?) Is she having dinner at the moment?}$