This sonata is one the late period works of Beethoven and it has a romantic and operatic approach in terms of style and tonal plan.
The main theme, which lasts 11 measures, can be divided into two parts. The first 4 measures and last 7 measures are in antecedent and consequent relation. Theme placed between 5-11 has an aria character and the bass line has an accompaniment role. In transition (bar 12-19), rhythm is accelerated and the upper line has a passage work with broken chords. Subordinate theme area is divided into three parts. In the initial part (bar 20-27), the tonality or the subordinate key is not clear because the theme starts as it is in home key. Later on, it clearly modulates to subordinate key. Medial part (bar 28-33) is where the subordinate key is fully established. It is clearly in E flat major. Closing part (34-39) is on tonic pedal and it immediately links to development.
Development is a little bit short and it lasts only 15 bars (40-55). It is in relative minor key and uses the first 4 bars of main theme as its material. Throughout the sequences of main theme, it modulates to f minor, D flat major and b flat minor. It is non-normative that there is no retransition as the sequences of main theme links to recapitulation.
Recapitulation starts with the main theme in bass line and it is like a continuation of development since both of them uses the main theme as its material. The continuation part of main theme (bar 5-11 of exposition) is stated differently in recap as it is in D flat major with an enharmonic modulation to E major. Transition (bar 70-75) starts in E major and it links to subordinate theme. The initial part of subordinate theme first comes in E major but afterwards it is stated again in home key. The medial and closing parts of subordinate theme are stated exactly in recapitulation, there is no tonal difference from exposition.
A small coda (bar 105-116) closes the whole movement and it uses transition and fragmentation of main theme as its material.