Using future, but I am also doing the action now?
 

Hi all,

We recently learned about the future tense and it seems straight forward enough but what if I want to say I will do something (in the future), but I am also doing it now?

For example:

Tendré cuidado hasta que el ejército se vaya de la ciudad.
I will be careful until the army leaves the city.

In the spanish sentence I wrote it sounds like I will have caution in the future, but I'm trying to communicate that I am being careful now and will continue to be careful until the army leaves.

Any ideas?

Gracias.

The sentence is proper and quite correct.

Tendré cuidado hasta que ...

means the time span bracketed this way:

"From this instant on, and until what follows the conjunction que happens."