Spoken language is notorious for its long and complex sentences, full of digressions and filler words. It is also not uncommon for the speaker to change their mind and simply give up on the original beginning of the sentence, and finish it in a totally unpredictable way. This unpredictability is the exact reason why the simultaneous interpreter should aim for simple sentences in their translation, and the way to achieve this is by dividing a long, complex text into short clauses. This is called the salami technique, because the text is sliced like salami.
Simultaneous interpreting requires the interpreter to translate the spoken source text, while at the same time ensuring the target word choice and grammar are correct and listening to the source text they are yet to translate and keeping it in their short-term memory until the translation of the previous segment is done. Since this is a complex and tiring task, the industry standards require pair work, where two interpreters alternate every 30 minutes.