What do you exactly mean by "equivalent of Old English"? An earlier form of the language that belongs to the same subgroup? (so for example Germanic languages in the case of English)

Perhaps it is a question for /r/linguistics, but I can already give you examples of earlier forms of different languages:

• French : Old French
• Swedish : Old Swedish, that itself evolved from a dialect of Old Norse
• Japanese : Classical Japanese
• Malay : Old Malay
• Javanese : Old Javanese

And so on. Basically any language that is spoken today evolved from an earlier form of this language, and even current languages still evolve (new words, change in grammatical rules, ...).

hi! This FAQ section is mostly full of English examples, but you'll find a few posts (and scattered comments) on a few other languages

• How far back could I go and still communicate?