How are Spanish and Persian connected to Proto-Indo-European?

Spanish and Persian are both members of the Indo-European language family, meaning they share a common, hypothetical ancestor known as Proto-Indo-European (PIE). While no written record of PIE exists, linguists have reconstructed it by identifying systematic correspondences in vocabulary and grammar across its descendant branches.123

The connection for each language follows distinct evolutionary paths:

• Spanish: Spanish belongs to the Romance branch, which evolved from Latin. Latin itself was part of the Italic branch of the Indo-European family, tracing its lineage back to PIE.43
• Persian: Persian is part of the Iranian subbranch of the Indo-Iranian branch. This branch diverged from the PIE ancestor and eventually split into Indic and Iranian groups, with Persian (including Old Persian and modern Farsi) developing within the Iranian line.43

These languages are linked by their shared descent from this ancient, reconstructed language, which was likely spoken approximately 6,000 years ago.14