the first part of the phrase is heard in measures 1-4 and the first cadence of the piece immediatly tonicizes the V chord (measure 4). the piece does not immediately modulate, but instead provides foreshadowing...intriguing, eh? in the next four measures, the melody is not repeated, but a new melody is heard, so the phrases differ. in the 8th measure, an imperfect authentic cadence terminates this phrase, and segues almost directly to the next cadential point heard four measures later (measure 12). i interpreted this as an elision, " the connection of two phrases in such a way that the cadential point of the first coincides with the beginning of the second." although the imperfect authentic cadence feels fairly stable, the melodic line keeps moving towards a new harmonic goal and then modulates to a new key. i would also say that the phrases are asymmetrical because the first four measures can be chunked together, and the eight consecutive measures drive towards the final cadence.