Learn Hardcore Greek: Το παιδί περπατάει αργά μέχρι το σχολείο.

Modern Greek present covers both English simple and progressive aspects. So Το παιδί περπατάει… can mean either “The child walks…” (habitual) or “The child is walking…” (right now). Context decides:

Κάθε μέρα, το παιδί περπατάει… = habitual
Τώρα, το παιδί περπατάει… = happening now

Why is the definite article το used before σχολείο, when English often says “to school” without “the”?

Greek typically uses the article with nouns, even with places. With institutions, there’s a contrast:

πάω σχολείο = I attend school (institutional, no article)
πάω στο σχολείο = I go to the school (the building/place) With μέχρι, you almost always use the article: μέχρι το σχολείο (“up to the school”).

Why το παιδί and not η/ο παιδί? What gender is παιδί?

Παιδί is neuter, so it takes the neuter article το. In Greek, words referring to children (and many young animals) are often neuter: το παιδί, το αγόρι, το κορίτσι. The grammatical gender doesn’t necessarily match biological sex.

What cases are used in the sentence?

Το παιδί is nominative (subject).
το σχολείο is accusative, because in Modern Greek most prepositions, including μέχρι, take the accusative.