Až přijede babička z nemocnice, připravím jí polštář a deku v pokoji.

When grandma comes back from the hospital, I will prepare a pillow and a blanket for her in the room.

Breakdown of Až přijede babička z nemocnice, připravím jí polštář a deku v pokoji.

• já: I
• a: and
• v: in
• pokoj: the room

Questions & Answers about Až přijede babička z nemocnice, připravím jí polštář a deku v pokoji.

Why do přijede and připravím look like present-tense forms if the sentence is about the future?

Because both verbs are perfective:

• přijet = to arrive, as a completed event
• připravit = to prepare, as a completed event

In Czech, the present forms of perfective verbs usually express future meaning:

• přijede = she will arrive
• připravím = I will prepare

So this is completely normal Czech. If you wanted an imperfective idea such as an ongoing process, you would use a different verb and a different future form.

What does až mean here, and why not když?

Here až means when / once in the sense of a future point in time.

It suggests this sequence:

1. Grandma arrives.
2. Then I prepare the pillow and blanket.

For a single future event, až is the most natural choice.

Compare:

• Až přijede... = When / Once she arrives...
• Když přijede... can sometimes be heard, but když is more often associated with when/whenever in a general or repeated sense.

So až is a very typical word here.