Learn Turkish: Toz almak beyhude bir çaba, kaldı ki nasıl olsa yine tozlanacak. - Dusting is a futile effort; besides, it will get dusty again anyway.

Nasıl olsa specifically points to an inevitable outcome. It means that no matter what happens or what you do, the end result will be the same (anyway). While you could use zaten (already/anyway) to mean something similar, nasıl olsa puts a stronger emphasis on the futility of trying to avoid the future outcome.

What exactly does the phrase kaldı ki do in this sentence?

Kaldı ki is a conjunction used to introduce an additional, often stronger, point that supports your previous statement. It translates to 'besides,' 'moreover,' or 'what's more.' While it literally translates as 'it stayed that,' as a set phrase it is perfect for piling on a second reason why dusting is a waste of time.

Why is 'dusting' translated as toz almak but 'get dusty' is tozlanacak?

Turkish uses entirely different logic for removing dust versus accumulating it. Toz almak literally means 'to take dust' (wiping it away from surfaces). Conversely, tozlanmak uses the suffix -lan, which often means 'to acquire' or 'to become covered in.' So, tozlanacak literally means 'it will acquire dust.'

Is beyhude a common word for 'futile' in daily conversation?