"It is likely that they do not eat."
Translation:Es probable que ellos no coman.
Could someone please explain why the imperative/subjunctive tense should be used in this sentence? Is it related in some way to the fact that the statement is indefinite?
How is this an "impersonal expression"? It's conjecture and thus needs the subjunctive mood.
Impersonal Expressions with the Subjunctive
Impersonal expressions work a lot like emotions in that they express someone’s opinion or value judgement. They focus on the subjectivity of the statement and not on the actual truth or reality of the situation. Learn more about impersonal expressions here.
Es necesario que Jaime lea este libro. It is necessary that Jaime read this book.