Why subjunctive?

[PG12345]

This is a question from a DELE exam where you have to fill in the blank.

'ya han pasado la queja a la sección de sugerencias y reclamaciones y que me informarán cuando __________ algo.

Options are sabrán, sepan or sabrián and the correct one is sepan (subjunctive).

Im struggling with why the present subjunctive would be used rather than future 'when they will know something'

Thanks

[chileno]

No. In English it is the same thing...

They will inform you when they know more about that (etc)

[Rusty]

The present subjunctive is used when talking about a future event (because of its uncertainty). The future subjunctive is all but dead. It isn't used in everyday speech.

[PG12345]

Thanks. So in which cases would I use the simple future, only when I am sure an event will take place (for example estoy segura que comeré a las seis or volaré en 15 Junio). I thought the simple future could be used to make an assumption about the future (for example él trabajará bien en un equipo - a job interviewer making an assumption about a prospective candidate).

I wish I had been taught the subjunctive earlier haha!

Thansk again

Sorry, just realised I should have been clearer in my first post, I wasnt sure why the subjunctive was used instead of simple future, not instead of subjunctive future

[Rusty]

You can use the future tense in all the ways you suggested. However, when you add the 'cuando' clause attached to an event that takes place in the future, you must use the present subjunctive. You can never be certain the 'cuando' event will occur.

[PG12345]

Ah, thanks. I have a list of prompts for words/sentences which will use the subjunctive, I think I need to review it and learn the prompts.