"The woman is drinking water."
Translation:Kvinnen drikker vann.
Kvinnen er drikker vann is the literal, word by word, translation from English but it actually translates to "The woman is is drinking milk/The woman is drinks milk" which, obviously, isn't proper syntax.
There is only one present tense in Norwegian which you form by adding -r to the infinitive form of a verb (there are exceptions!).
- å drikke (to drink) + r --> drikker
It can be either be translated as Present Simple or Present Continuous. Adverbs and context are used to differentiate between the two.