Learn Spanish (Latin America): Para cuando termines el manuscrito, la imprenta estará cerrada. - By the time you finish the manuscript, the printing press will be closed.

The phrase para cuando ("by the time") introduces a future deadline. Because this finishing moment hasn't actually happened yet, Spanish requires the present subjunctive (termines) to show that it is anticipated. Note that you can never use the future tense immediately after time expressions like cuando or para cuando.

Could we ever use the indicative after para cuando?

Yes, if you are talking about a regular habit or a completed past event. For example, if you wanted to say "By the time you (usually) finish..." you would use the present indicative: Para cuando terminas.... But because this specific sentence looks forward to a future, uncompleted event, the subjunctive is required.

What does adding para to cuando change about the sentence's meaning?

If you just say Cuando termines, it simply means "When you finish." Adding para creates the phrase para cuando ("by the time"). This emphasizes a deadline, framing the second action (la imprenta estará cerrada) as a state that will already be true at the exact moment the first action happens.

Why is it estará cerrada instead of será cerrada?