Are Latin, Greek, English, and Balto-Slavic all living, guttural, Indo-European, dead, or Romance languages?
Latin, Greek, English, and Balto-Slavic are all Indo-European languages.
The Proto-Indo-European language was spoken by a prehistoric people group in Eurasia. Their language became the ancestor of the Indo-European languages.
These languages are spoken by about half of the world's population!