Condensation on the glass on the inside of a window is a nuisance and can lead to mould forming which can have health implications. The cause is usually a build up of moisture in the air located within a property combined with a cold surface.

Cooking, showering and even just breathing, without adequate ventilation will lead to a rise in humidity, the moisture carried within warm air cools around a cold surface, as the air cools the amount of moisture the air can carry reduces causing the excess moisture to be deposited onto the cold surface.

The best action you can take is to manage the moisture content of the air within your property. Increased ventilation (open the window more regularly) will help, if this isn't really an option then trickle vents can be retro fitted to the existing windows. 

Another option to explore is by changing the glass units in your existing windows to energy efficient glass units, this will not only provide better thermal efficiency, by keeping the internal glass surface in the window and the property warmer, it would help to manage the degree of condensation experienced.