wiadomo

In a sentence

• Wiadomo, że dziś będzie padać deszcz.

  It's known that it will rain today.

  Here, 'wiadomo' is used to mean 'it's known', indicating shared or general knowledge.

• Chodźmy na spacer, wiadomo, z parasolem.

  Let's go for a walk, obviously with an umbrella.

  In this context, 'wiadomo' conveys 'obviously', indicating an assumed necessity or condition.

• Nie będziemy ryzykować, wiadomo.

  We will not take risks, of course.

  Here, 'wiadomo' is used colloquially to mean 'of course', asserting agreement with or reinforcement of a statement.