Quick questions on Harmonising a melody with primary chords explained: O-Level Music

The three primary chords are built on the first, fourth and fifth degrees of the scale, and between them they contain every note of the major scale:

The phrase ends are the structural pillars, so decide their cadences before anything else, choosing the chords from the melody's ending notes:

Working between the cadences, give each main melody note a primary chord that contains it. Where a note fits more than one chord, choose the one that flows best from the previous chord (smooth progressions include I to IV, IV to V, and V to I). Keep a steady harmonic rhythm, often one chord per bar or per two beats, rather than changing chord on every note.

Put the chord roots in the bass, but choose octaves and the chord order so the bass line moves reasonably smoothly rather than leaping wildly. A bass that mostly steps or makes small leaps supports the harmony better than one that jumps about.

Fix the phrase-end cadences first; they are the pillars the rest is built around.

Put the roots in the bass but choose octaves and chord order so the bass moves smoothly, not in wild jumps.

Name the primary chords and the scale degrees each contains. [3 marks]

A phrase ends on the tonic. Suggest a cadence and the chords, and name it. [2 marks]

Explain why you should plan the cadences before harmonising the rest of the melody. [2 marks]