IPA: /ˈproʊtəˌlæŋɡwɪdʒ/
KK: /ˈproʊtəˌlæŋɡwɪdʒ/
A type of language that is believed to be the early form or ancestor of a group of languages.
Linguists study protolanguages to understand how modern languages evolved.
Protolanguage is formed from "proto-" (meaning first or original) and "language" (from Latin "lingua", meaning tongue or speech). The term refers to a hypothetical, reconstructed ancestral language from which a group of languages is derived.
Think of 'proto-' meaning first, and remember that a protolanguage is the original language from which others develop.