Learn Hardcore Esperanto: Mia kapo estas peza.

Estas is the copula, meaning “is” in this context. In Esperanto, verbs do not conjugate for person or number. No matter what subject you have, estas remains unchanged, which simplifies the verb system quite a bit compared to English.

How does the possessive adjective mia work here, and why isn’t it marked differently?

Mia means “my” and acts as a possessive adjective modifying kapo (“head”). In Esperanto, possessive adjectives agree in number with the noun they modify. Since kapo is singular, mia remains in its singular form. If you were talking about multiple heads, you would use miaj kapoj.

Why does the adjective peza end with -a, and how do adjectives generally work in Esperanto?

In Esperanto, adjectives typically end in -a. The ending signals that the word is an adjective. When the adjective directly describes a singular noun, it stays in this basic form (as in peza for “heavy”). If the noun were plural, you would add the plural ending -j to the adjective, making it pezaj.

What is the sentence structure of “Mia kapo estas peza” compared to English?

The structure is quite similar to English: a subject (mia kapo), followed by a linking verb (estas), and then a predicate adjective (peza). This subject + verb + predicate adjective order is standard in Esperanto for describing states or qualities.