Questions & Answers about Я совершенно выдохнулся и больше не могу спорить.
How does the вы- ... -ся pattern create the meaning of выдохнулся?
The combination of the prefix вы- and the postfix -ся indicates doing an action to the point of absolute saturation, completion, or exhaustion. The root here relates to breathing (выдох means an exhale). So, выдохнуться literally means "to exhale oneself completely," which metaphorically means to run out of steam or become totally exhausted.
Why is совершенно used here instead of очень?
Очень (very) is generally used with gradable states or actions. Because выдохнуться describes reaching an absolute limit or a final saturated state, you can't be "very" exhausted in this specific sense—you are completely drained. Совершенно (completely/absolutely) is the natural choice for emphasizing this kind of limit.
Is there a reason for the word order in больше не могу?
While не могу больше is also grammatically correct, placing больше immediately before the negated verb (больше не...) is the most standard and natural Russian word order for expressing "not anymore" or "no longer."
Why is спорить in the imperfective aspect?
The speaker is saying they can no longer continue the ongoing process of arguing. When не мочь is used to say you no longer have the physical or mental energy to keep doing what you were already doing, the following infinitive is usually imperfective.