Learn Dutch: Ik versta de docent niet. - I do not understand the teacher.

In Dutch, niet comes after a specific direct object. Because de docent (the teacher) has the definite article de, it counts as a specific object. Therefore, niet is placed after it, which pushes it to the end of the sentence.

Why does the sentence use versta instead of begrijp for understand?

Dutch has two different words for understanding. You use verstaan when you physically hear and make out the words being spoken (like when someone mumbles or a room is noisy). You use begrijpen when you mentally grasp a concept or meaning. This sentence implies the speaker literally cannot make out the words the teacher is saying.

The English translation says do not, so why is there no word for do in the Dutch sentence?

English uses helper words like do or does to make a negative sentence, but Dutch does not do this. To say you do not do something, you simply use the main verb (versta) and add niet to the sentence.

Is there a difference between docent and leraar?

Both words mean teacher. Leraar is very common for primary and high school teachers, while docent is slightly more formal and is also used for college and university instructors.