"Kwa nini unafua?"
Translation:Why are you washing?
Just to be clear, this is asking "Why are you washing clothes?" Washing anything else will use a different verb, so "clothes" should probably be in the English translation.
In UK English I would say "doing the washing", which is only for clothes.
in Swahili language, there is more than one word for washing e.g kufua to wash clothes kunawa= to wash hands kuosha= to wash the utensils