Can't a casement window be fitted with a window screen?

You can install the screen. Window grilles refer to the artistic glass on the window, which is installed inside the window frame, while screen windows are window accessories used to prevent insects and excessive sunlight from entering the room. Generally installed on the window sill or window frame, the installation positions of the two do not conflict. Screen windows can be installed with window grilles. The casement window is a style of windows in private houses, and the sash moves in a certain horizontal direction, so it is called casement window.