"Is this their juice?"
Translation:זה המיץ שלהן?
I've heard it given in an interview on YouTube. Would you say the interviewer was not speaking "normal" conversational Hebrew?
If we were simply asking "Is the juice theirs", we would say המיץ שלהן? or האם המיץ שלהן?; however since we are asking "Is this their juice", we say זה המיץ שלהן? or האם זה המיץ שלהן. Knowing how to correctly use זה in such contexts can be a little tricky. It depends on what you want to emphasise. For instance, if we wanted to ask "Is this juice theirs?" we would say המיץ הזה שלהן?, giving the juice a definite article.