or just a little above the ankle and twill jogger pants. A kilted skirt is sometimes worn, especially in schools with predominantly Celtic student populations. In some parts of Canada, the skirt has been modified to include an attached pair of shorts beneath, for modesty called a skort. Bike shorts or Leggings are often worn under girls' skirts or jumpers for modesty and to prevent individuals from looking under the girl's skirt or dress. The leggings can be ankle length or capri length with crew or knee-high socks worn over the ankle leggings. Culottes or ankle pants that stop at or just above the ankle are also sometimes substituted for a skirt, especially at non-parochial private schools; however, for special events, the skirt is usually still worn. Also knee socks or tights are two other commonly worn items with the skirt. Students in preschool and, less frequently, kindergarten, are held to be more likely to engage in messy activities. As such, they may be asked to wear their school's physical education uniform as their regular uniform. Younger girls are often seen wearing plaid jumpers over a blouse under their skirts. Many schools require a jumper up to the fourth, fifth, or sixth grade, presumably because the lifestyles and habits of younger girls may make blouses more likely to become untucked from skirt or culotte waistbands. They are often worn with tights or knee socks and flats, sperrys, or sometimes dressy sneakers. After that, the jumper is often discarded in favor of a plaid skirt with bike shorts, capri or ankle length leggings, with crew or knee socks over the ankle leggings, tights, knee socks or culottes and blouse or polo depending on the weather and season. Often the skirt and blouse or polo must be worn with a sweater or sweater vest, or the polo is worn by itself or with a layering long-sleeved tee underneath or with the polo worn underneath a sweater or sweatshirt with the polo collar turned over the sweater or sweatshirt collar so it's visible. Usually flats, or Sperrys, and sometimes other dressy shoes are worn. Boys typically wear a collared shirt and tie or polo shirt, and slacks of required colors. Twill jogger pants are becoming a comfortable but still appropriate uniform pants choice worn by boys. Polo shirts have to some extent replaced dress shirt. In the winter colder months the polo is