Final answer:
The phrase 'Es imposible que...' is written in the subjunctive mood, expressing impossibility or hypothetical situations.
Step-by-step explanation:
The phrase 'Es imposible que...' is written in the subjunctive mood. The subjunctive mood is used to express wishes, suggestions, requirements, or hypothetical situations. In this case, 'Es imposible que...' is stating the impossibility of something happening. For example:
Es imposible que llueva mañana. (It is impossible for it to rain tomorrow.)
The subjunctive mood is also often used after certain expressions such as 'es necesario que' (it is necessary that), 'es importante que' (it is important that), and 'es mejor que' (it is better that).