The Neapolitan Sixth chord is commonly used in 1st inversion. Yet, we find examples in 2nd and even root position. This is an example of the chord in root position from Chopin's Prelude #20. The key is C minor so the Neapolitan sixth chord is Db major.
Sometimes the Neapolitan Sixth chord is followed by an auxiliary diminished 7th chord of the V degree. Bach's G minor choral Ach Gott, vom Himmel sieh' darein offers a good example:
The following excerpt is from the Andante of Mozart's Concerto K 488. Click the measure were you find the Neapolitan Sixth chord. The Neapolitan Sixth chord appears in two measures, can you find those measures? Ask yourself, if the key of the piece is F# minor, what major chord is half-step above? You will probably find the chord in first inversion:
Click the measures where you see a Neapolitan Sixths...