the verb 'sweep' originates from middle english 'swepen', which is likely of old english origin, though its exact proto-germanic ancestor is unattested. it is related to middle english 'swope', meaning 'to sweep', and may be connected to old norse 'sveipa', meaning 'to swoop, swing, throw'. the development of the irregular past tense 'swept' follows a common pattern in english where verbs with a final voiceless consonant (like /p/ in 'sweep') form their past tense by adding a /t/ sound and undergoing an internal vowel change, a process known as ablaut. this places it in the same class as verbs like 'keep/kept', 'sleep/slept', and 'weep/wept', where the modern form is a fossilized remnant of old english strong verb conjugation patterns that have been regularized in a specific, now irregular, way.

the word 'swept' is a fully fused past tense and past participle form of the verb 'sweep'. it is not productively segmentable into distinct morphemes in modern english.