'frequently' originates from Latin, specifically the word 'frequentia,' where 'frequent-' meant 'crowded or repeated.' 'Built' comes from Old English 'byldan,' meaning 'to construct.'

'frequentia' transformed into the French word 'fréquent,' and eventually became the modern English word 'frequent.' 'Byldan' evolved into the modern English word 'build.'

Initially, 'frequent' meant 'crowded or repeated,' but over time it evolved into its current meaning of 'often.' 'Build' has largely retained its original meaning of 'to construct.'