Linguistics
Some languages force every verb to flag whether the next subject changes
In switch-reference languages, a verb ending doesn't just mark tense — it marks whether the next clause's subject stays the same or changes, something English conveys only through context. Papua New Guinea's Amele, described by linguist John Roberts, chains long runs of clauses this way, tagging nearly every verb 'same subject' or 'different subject'. Linguists have since found the feature in unrelated families worldwide, from Native American languages to the New Guinea highlands.