the word 'this' originates from the old english demonstrative 'þes' (masculine), 'þeos' (feminine), and 'þis' (neuter), which meant 'this, this one.' it is derived from the proto-germanic demonstrative base þa-, also the source of old saxon 'these,' old norse 'þessi,' and gothic 'þata.' this germanic root is further traced back to the proto-indo-European demonstrative pronoun to-, which also gave rise to latin 'iste' (that) and greek 'ho' (the). the core function of 'this' has remained remarkably consistent for millennia: to point to or specify a particular entity that is near in space, time, or thought to the speaker, distinguishing it from others that are farther away.

this is a simplex word of old english origin. it is a demonstrative pronoun and determiner whose form has remained largely unchanged from its proto-germanic ancestor.