What is another word for the one question?
Pronunciation: [ðə wˈɒn kwˈɛst͡ʃən] (IPA) 
The phrase "the one question" can be interchanged with a variety of synonyms. It could be referred to as the key inquiry, the essential query, the fundamental concern, the pivotal issue, or the primary matter. Depending on the context, it could also be called the core proposition, the central problem, the crucial point, or the critical aspect. It can be beneficial to have a diverse lexicon when writing or discussing a particular topic to avoid repetition, and these alternative phrases for "the one question" can add clarity and variety to one's language. Choose the best synonym that will fit your writing or conversation.
