How is this word, "smutsiga", differnt from "smutsig"? Like, I know they mean the same, but when do you use these different forms?
Smutsig will be used when the noun it refers to is singular. In this sentence the word 'kläder' is always plural, so we use 'smutsiga'. Also, the noun kläder is used along with a possesive (hennes) which also makes the adjective end in 'a'