Questions & Answers about Peta cipele je istrošena.
Why is the word for shoe in the form cipele here? Doesn't that mean "shoes" in the plural?
While cipele is indeed the nominative plural form for "shoes", here it is being used in the genitive singular case, meaning "of the shoe". The genitive case is often used to show possession or belonging. If the sentence meant "the heel of the shoes" (plural), it would use the genitive plural form instead, which is cipela.
Does the adjective istrošena (worn out) agree with peta or cipele?
It agrees with the main subject of the sentence, peta (the heel), which is feminine singular. The word cipele is just a modifier in the genitive case telling us which heel is worn out, so it doesn't dictate the gender or number of the adjective at the end.
The adjective istrošena means "worn out". How does the prefix is- change the meaning of the base verb?
It comes from the perfective verb istrošiti. The base verb trošiti means "to spend" or "to consume" (imperfective). The prefix is- (which is a sound-changed form of iz-) adds the meaning of doing something to absolute completion. So, the heel hasn't just been used; its utility has been completely exhausted or worn down.
Could I use a possessive adjective and say Cipelina peta je istrošena instead?