Questions & Answers about Ο κινητήρας λειτουργεί καλά.
Ο is the masculine singular definite article, so it means the.
In Ο κινητήρας λειτουργεί καλά, it goes with κινητήρας and shows that the noun is definite: the engine.
A few useful article forms to compare:
- ο = the for masculine singular nouns
- η = the for feminine singular nouns
- το = the for neuter singular nouns
So ο κινητήρας = the engine.
Κινητήρας is a masculine singular noun, and -ας is a very common ending for masculine nouns in Greek.
In this sentence, κινητήρας is the subject, so it appears in the nominative singular form:
- ο κινητήρας = the engine
If you keep studying Greek, you will see that nouns change form depending on their role in the sentence. For example, masculine nouns in -ας often have different endings in other cases.