Berklee II, I found these two terms.
It defines them:
An approach note is a note which is a quarter note or less in duration and which moves by step to a chord tone or available tension. Approach notes are found in many configurations.
Passing tones are approach notes which move by step between two chord-tones, between two available tensions, or between a chord tone and tension (or viceversa)
1) A passing tone is a kind of Approach Note, approach notes goes TO a chord tone or available tension, and passing tones goes FROM and TO chord tones or available tensions?
2) Approach notes are never located in the first beat of a measure?
Extended dominantes are either dominant or secondary dominant chords placed at strong stress points, meaning that if in a piece in C major (for instance) one places a D7 (V/V) in the third beat of a measure it would be a simple secondary dominant; but if it was placed at the beginning of that measure it would be a extended dominant? Does it means that the extended dominant's time duration should be longer than the resolution?