How does Nikon d5500 take photos with blurred background? 18 ~ 55.

It is more difficult. The aperture of 18-55 is not large enough, and the focal length is short.

Four elements of shallow depth of field: large aperture, long focal length, short lens distance and far background.

You shoot with 55 ends, the aperture is 5.6, the shooting distance is closer and the background is as far as possible. But the blurring effect will not be very good.