The word 'those' originates from the Old English plural demonstrative 'þās', the plural form of 'þēs' (this). It is part of the ancient Germanic demonstrative pronoun system, which itself derives from the Proto-Indo-European demonstrative stem to-. This root is the ultimate source for a vast family of determiners and pronouns across Indo-European languages, including 'the', 'that', 'they', and 'them'. The specific form 'those' developed through regular sound changes in Middle English, where the Old English 'þās' evolved, influenced by the plural '-s' ending and the vowel in the related word 'those' (from Old English 'þā'). It solidified in its modern spelling and pronunciation to serve as the standard plural counterpart to 'that', pointing to items that are specifically identified but not near the speaker.

The word 'those' is a simplex form, a direct descendant of the Old English plural demonstrative pronoun 'þās' (nominative and accusative). It is not productively segmentable into distinct morphemes in modern English.