This piece has two major sections. The first section is in Bb major and ends with a IAC at measure 8, though this cadence is complicated by the large number of non-chord tones in the top voice including a C# on the downbeat of the I chord that resolves to D. The meter is 3/4 and the accompaniment does a pattern of the bass note on 1 and upper chord notes on 2 and 3.
The B section (m. 9-24) is very different from the A section. The key changes to g minor. The tempo becomes slower and has more rubato. The accompaniment turns to arpeggiated eighth notes. The dynamics are softer than the A section. This section has two half cadences on the V7 which is accentuated by pauses on these chords.
The B section then undergoes a transition to the A section (m. 25-32). The key returns to Bb major and the melody and accompaniment are similar to that of the A section but the dynamics and tempo are the same as the B section.
This leads back to a full return of the A section (m. 33) with an exact repetition of the A theme for the first few bars, but then changes to a descending line that anticipates the final cadence, which is an IAC that doesn't have the non-chord tones of the first A section which gives the song a feeling of an ending.