This sonata is unique in the whole cycle since its subordinate key areas are quite out of norm.
The main theme has an asymmetrical 8+5 sentence structure. First 4 bars are basic idea and it is repeated on flattened 7 (B flat) between 5-8. This is the presentation part of sentence. Between bars 9-13 is where the continuation is presented and it is resulted with a half cadence. Transition takes place between 14-34 and it can be divided into two parts. The first one (14-22) is like the repetition of main theme but this time the repetition of basic idea is on supertonic (II) degree. The second part of the transition has a purpose of standing on dominant degree of III.
Subordinate themes, which are unique for this sonata, are in mediant degree. This area can be divided into two as it contains two subordinate themes. First theme is placed between 35-49. Theme is a period and it is very homophonic. Between bars 42-49, melody is placed in the bass line and it is accompanied in the upper line. It is no more homophonic. Shortly, the first part is in a quite tight structure since the theme is a period. However, the second subordinate theme group is looser. Its initial part is between 50-61 and it consists of broken chords. Later on, a cadential part (62-73) is presented with an acceleration in harmonic rhythm. This part is actually where the subordinate key is fully confirmed, therefore between 74-87 is a codetta like section in which many plagal cadences occur.
Development begins with the main theme in F Major and between 94-111 it turns into a section in which the fragmented ideas of main theme are developed. Between bars 112-141, the second subordinate theme is developed with many secondaries and sequences. In the words of Hepokoski, this development is a full-rotational one since it uses musical materials both from main theme and subordinate theme. Retransition takes place between 142-155 as it stands on dominant in order to prepare recapitulation.
Recapitulation is not different than exposition in terms of form, except the presentation of subordinate theme is in submediant degree. Yet, Beethoven balanced this non-normative approach by presenting subordinate theme once more in the home key. Sonata ends with a long, “full-rotational” coda. It uses again materials from main theme and subordinate theme. In this coda, every non-normative approach, in terms of tonal plan, is reseted and the home key is fully confirmed.