"The window is dirty"

Translation: Dirisha ni chafu

[BwanaSimba]

This seems a direct translation from English to me. As "-chafu" is an adjective, i believe it is "dirisha chafu", like you say "hewa safi" instead of "hewa ni safi".
N.B. Even when the use of "ni" is grammaticaly correct, i found that often "ni" is omitted, like people say "mimi Mtanzania" rather than "mimi ni Mtanzania".

[pixilico]

Why "lina" instead to "ni"?

[pixilico]

Oh, right! "lina uchafu" = has dirty | "ni chafu" = is dirty.

[AGreatUserName]

Yeah, uchafu is a noun "dirt" or "dirtiness"

[pixilico]

Thank you!