Question

Please elaborate more and make it in a paragraph form. Do not just copy and paste from the internet.

Answer 1

Even if you don't put any pressure, you can still have liquid water at sub-zero temperatures using additives. Additives such as salt can interfere with the chemical bonding needed to form a solid and they therefore can lower water's freezing point. Salt is made of strong sodium and chlorine ions. When dissolved in water, the water molecules tend to stick to the salt ions instead of to each other, and they therefore don't freeze as readily. As you add more salt to water, its freezing point continues to drop until the water reaches saturation and cannot hold any more salt. If you add enough salt, the freezing point of water can be dropped as low as -21 degrees Celsius. This fact means that water at -21 degrees Celsius can still remain liquid if enough salt is added. Instead of keeping liquid water from freezing, this powerful property of salt can also be used to turn ice back into water. Sprinkling salt on icy sidewalks lowers the freezing point of the ice below the ambient temperature and the ice melts.

Yes, water can stay liquid below zero degrees Celsius. There are some  ways in which this can occur such as;

First and foremodt, the phase of a material relies strongly on both its temperature and pressure. For most liquids, putting pressure increases the temperature at which the liquid freezes to solid. A solid is developed when the loose, meandering molecules of a liquid is not sufficient and close enough to develop more stable bonds that pin them in place. When we put pressure to a liquid, we force the molecules to get closer together. They can therefore form stable bonds and become a solid even if they have a higher temperature than the freezing point at standard pressure. Water is somewhat unique, though. Water molecules spread out when they are bonding into a solid crystalline structure. This spreading-out action leads ice to be less dense than liquid water, causing ice to float. This spreading-out action of the water molecules during freezing also means that applying pressure to water lowers the freezing point. If you apply enough pressure (making it hard for the water molecules to spread out into the solid structure), you can have liquid water several degrees below zero degrees Celsius.