Questions & Answers about Peter versucht zu schlafen, obwohl er nicht müde ist.
Why does the verb ist go at the very end of the second part of the sentence?
Because of the word obwohl (although). It is a subordinating conjunction, which means it introduces a dependent clause and forces the conjugated verb (ist) to the very end of that clause.
Could I just use aber (but) to express this idea?
You could say something similar: Peter versucht zu schlafen, aber er ist nicht müde. However, aber keeps the normal word order. Using obwohl (although) adds a stronger sense of contrast and requires the verb to be kicked to the end of the clause.
Why do we say zu schlafen instead of just schlafen?
Just like in English where we say tries to sleep, German uses zu + the infinitive (schlafen) after certain verbs. The verb versuchen (to try) almost always links to another action this way.
Why is nicht placed right before müde?
When you want to negate a specific adjective or state, nicht is placed directly in front of the word it is negating. Here, it negates müde (tired), so it sits right before it.