Hi Daniel, I hope I have answered this in time!
Most measures have multiple chords per measure, usually they change halfway through (the harmony changes each quarter note). For second chord, I will write as m. 2.5 to show it is halfway through the measure. The piece begins with a half measure pick-up, which I am labeling as m. 1. Each chord will be labeled in the following template:
measure number, figured bass symbol, (harmonic function), chord name, inversion
m. 1 I (tonic) E major root
m. 2 V6 (dominant) B major in first inversion
m. 2.5 vi (submediant) C# minor in root inversion
m. 3 iii6 (mediant) G# minor in first inversion
m. 3.5 IV (subdominant) A major root
m. 4 I6 (tonic) E major in first inversion
m. 4.5 V7 (dominant seventh) B major 7 root
m. 5 I (tonic) E major root
m. 5.5 I (tonic) E major root
m. 6 V6 (dominant) B major in first inversion
m. 6.5 V4-3 / V (secondary dominant seventh of V) F# major 7 in third inversion
m. 7 V (dominant) B major root
m. 7.5 V6-4 (dominant) B major in second inversion
m. 8 I6 (tonic) E major in first inversion
m. 8.5 I (tonic) E major root
m. 9 V6-4 (dominant) B major in second inversion
m. 9.5 V/V (secondary dominant of V) F# major root
At measure 17, we have modulated to the key of B major. The measure begins with an ascending scale beginning on A#, so it has a dominant kind of feel and could be labeled as V (dominant) or viio (leading tone). Starting after Tempo I:
m. 17.5 I6 (tonic) B major in first inversion
m. 18 V6-4 (Dominant) F# major in second inversion
m. 18.5 ii6 (super tonic) C# minor in second inversion
Here Beethoven starts modulating to the key of C# using secondary dominants
m. 19 V6-4 / ii (secondary dominant of ii) G# major in second inversion
m. 19.5 viio4-3 / ii (secondary leading tone of ii) B# diminished seventh in second inversion
Measure 20 could be considered the beginning of C# minor section, or it could be put off until m. 21, but 21 is definitely in C# minor and would be written as i (tonic)
m. 20 ii6 (super tonic) C# minor in first inversion
m. 20.5 V4-3 / ii (secondary dominant seventh of ii) G# major seventh in second inversion
m. 21 I (tonic) C# minor root
OR
m. 20 i6 (tonic) C# minor in first inversion
m. 20.5 V4-3 (dominant seventh) G# major seventh in second inversion
m. 21 i (tonic) C# minor root
m. 33 is a little trickier. I would say it is in the key of D# minor.
m. 33 i (tonic) D# minor root
m. 33.5 V (dominant) A# major root
m. 34 i (tonic) D# minor root
m. 34.5 moves away from the key of D#, giving is a C# major root chord
I hope this helped!
