Learn Dutch: Na het werk moet hij rusten. - After work he has to rest.

Because the sentence starts with the time phrase Na het werk (After work). In Dutch, the conjugated verb (moet) must be the second piece of information in the sentence. To keep it in second place, the subject (hij) swaps places with the verb.

Why is rusten at the very end of the sentence?

Moeten (to have to) is a modal verb. When a sentence has a modal verb, that modal takes the second position, and the main action verb (rusten) gets pushed to the very end of the sentence in its full dictionary form (the infinitive). Understanding this "sandwich" structure is key for when you start adding separable verbs later!

Why use moet if the English translation says "has to"? Isn't moet translated as "must"?

In Dutch, moeten covers both "must" and "to have to". While "must" can sound very strict or formal in English, moeten is the perfectly normal, everyday word for any kind of obligation in Dutch.

Why is there a het before werk? In English we just say "after work" without an article.

Dutch often uses definite articles (de or het) in standard expressions where English drops them. For daily routines, you will frequently see phrases like na het werk (after work) or op het werk (at work).