Breakdown of Или они решат сдаться, или начнут спорить.
они
they
спорить
to argue
или
or
решить
to decide (perfective)
Questions & Answers about Или они решат сдаться, или начнут спорить.
Why is there a comma before the second или in this sentence?
When you use a double conjunction like или ... или (either ... or) to connect two parts of a sentence, Russian grammar requires a comma before the second part of the conjunction.
Why is спорить (to argue) imperfective, while сдаться (to give up) is perfective?
The verb начнут means 'will start'. In Russian, verbs of beginning, continuing, and ending must always be followed by an imperfective infinitive. You cannot start a completed action! On the other hand, решат (will decide) has no such rule, so it takes the perfective сдаться to show the action of giving up will be completed.
Why isn't the pronoun они repeated before начнут?
Just like in English, you do not need to repeat the subject if it is the same for both actions. The -ут ending on начнут already makes it completely clear that 'they' are the ones starting the action.
The verbs решат and начнут look like they are conjugated in the present tense. Why do they mean 'will decide' and 'will start'?
Both решить (to decide) and начать (to start) are perfective verbs. When you conjugate a perfective verb using standard present tense endings, it automatically forms the simple future tense, showing a result that will be achieved in the future.