Learn Spanish (Latin America): Aunque el barro está resbaloso, caminamos rápido. - Although the mud is slippery, we walk fast.

Because the slipperiness of the mud is a known, established fact right now. When aunque (although/even though) introduces a real fact that is currently happening, we use the normal present tense (the indicative). If we were talking about a hypothetical situation like 'Even if the mud is slippery tomorrow', we would use a different form (the subjunctive).

Why use está resbaloso instead of es resbaloso?

We use está (from estar) here to describe the current physical condition of the mud on this specific walk. While mud can be inherently slippery (ser), using está emphasizes how it feels right now at this exact moment on the ground.

Where does the word resbaloso come from?

It comes from the verb resbalar, which means to slip or to slide. The suffix -oso is often added to words in Spanish to turn them into adjectives, similar to adding a 'y' in English (like turning slip into slippery).

Why is it caminamos rápido and not caminamos rápidamente?