"The window has dirtiness"
Translation:Dirisha ni chafu
Strange: in English you would rather say the window is dirty. And in Swahili that is literally what it says, yet the English says the window has dirtiness. I'd expect dirisha ana uchafu than...
Since dirisha is a class five noun (dirisha - madirisha), the verb would probably have to begin with the prefix li: dirisha lina (instead of "ana")
In Kiswahili all the nouns are put into groups , there are about 12 main noun classes but 18 in total, each noun class has its own prefixes for verbs, adjectives... For example class five also known as the 'Ji/Ma' noun class, it has the subject prefixes 'Li(in the singular) and Ma(in the plural)'. Check out this link for more information, theres alot of useful resources on the internet for swahili. https://2seedsswahili.wordpress.com/2013/05/27/swahili-unit-4/
Also if you are on computer check out the tips section on each lesson, they explain the rules of the Swahili language in great detail.
I'm agreeing with Deborah. A class 5 noun is textbook terminology. Sometimes a good book helps a lot.
This one should definitely be "The window is dirty." I might be tempted to argue that even the other possible formulation of this sentence in Swahili "Dirisha lina uchafu" should still be translated "The window is dirty", because a native speaker of English would never say "The window has dirtiness." We might say, in (American) English, "The window's got some dirt/mud/oil/etc ... on it."