〜ている（結果・習慣）
A state resulting from a past action; a repeated habitmachine translation
FormationVerb て-form + いる
At N5 you learned 〜ている for actions in progress. At N4, you need to grasp its second use: a state that is the lasting result of an action that already happened. 結婚しています doesn't mean "is having a wedding" but "is married (and remains in that state)". Likewise: 知っています (know), めがねをかけています (is wearing glasses), 東京に行っています (has gone to Tokyo and is there now).
The verb 知る is a special case worth remembering: the affirmative is 知っています, but the negative is 知りません — you don't say 知っていません.
The third use is a repeated habit, often with 毎朝, 毎日, いつも: 毎朝公園を走っています (I run in the park every morning). Don't confuse it with 〜てある: 〜ている merely describes a state, while 〜てある always implies someone did it deliberately.
Examples
姉は結婚しています。
My older sister is married.
田中さんの電話番号を知っていますか。
Do you know Tanaka-san's phone number?
毎朝公園を走っています。
I run in the park every morning.