Questions & Answers about Leipä muuttuu vihreäksi homeeksi.
Why do both vihreä and home end in -ksi here?
The verb muuttua (to change into / to turn into) requires the result of the change to be in the translative case (-ksi). Since adjectives in Finnish must agree with the nouns they modify, both vihreä (green) and home (mold) take the ending, becoming vihreäksi homeeksi.
Could I use the verb muuttaa instead of muuttua in this sentence?
No, because muuttua is an intransitive verb, meaning the subject changes itself (the bread turns). The verb muuttaa is transitive, meaning someone or something changes something else. You would use muuttaa if an outside force was doing the changing, for example: Kosteus muuttaa leivän homeeksi (Moisture turns the bread into mold).
Why does the word home get an extra e before the case ending in homeeksi?
The noun home belongs to a group of older Finnish words that end in -e in their basic form (just like huone or perhe). When you add a case ending to these words, the final -e doubles to form the stem. So, home becomes the stem homee-, to which the translative ending -ksi is attached.