Learn Spanish (Spain): Mi madre trabaja a pesar de que está muy cansada. - My mother works even though she is very tired.

With a pesar de que, we use the indicative (like está) when we are declaring a known, established fact. The speaker is confirming that the mother is indeed very tired. If we used the subjunctive (esté), it would mean something closer to 'even if she might be tired' or would refer to a fact that the speaker acknowledges but doesn't want to focus on.

Since the subject is the same for both actions, could we use a pesar de + infinitive instead?

Yes! Because mi madre is the subject of both working and being tired, you can drop the que and use the infinitive: Mi madre trabaja a pesar de estar muy cansada. This is a very common and natural alternative.

Can I use aunque instead of a pesar de que in this sentence?

Yes, you could say Mi madre trabaja aunque está muy cansada. Both express the same idea, but a pesar de que (in spite of the fact that) is a bit stronger and more emphatic than aunque (even though).

Just as a quick reminder, why do we use estar (está) rather than ser (es) with cansada?

We use estar for physical states, moods, and conditions. Being tired (cansada) is a temporary state, so it always pairs with estar.