I don't know how this is taught, but I expect the first phrase should be treated like a appoggiatura "sighing" figure and the second as a lead-in to the beat.
It seems easier to describe in notation rather than words...
Both just decorate a descending
D major chord. The slurs and hairpins I added are more for visualization, not literal.
The first phrase, the "sighing" figuration doesn't really connect the repeating notes. The second eighth note of each beat is more a "release" of the first eighth on the beat. So, using the breathe metaphor,
D6 is breath in and the following
A5 is the releasing "sigh." The repeating notes like
A5 from the last half of beat 1 to beat 2 is incidental. You could imagine a break between each beat (the red line.)
The second phrase uses the repeating notes to lead-in to each beat. Instead of a clean break between beats you could imagine the emphasis crossing over the division between beats.
The first is a sort of "internal" treatment, staying inside each beat. The second is a "crossing over" the beat treatment. This reminds me of feminine and masculine phrase endings where the type is determined by the placement of the final note relative to the bar line, but the two phrases in question happen on a smaller scale.
In both cases you still have each beat preceded by a dynamically weaker note, which then is the same thing in both cases, and the thinking seems to get circular. Something else seems necessary to really distinguish the two cases. In the first, there will probably be a slight detached playing of the second eighth note of each beat, and over all there may be a kind of decrescendo from
D5. In the second case you probably want a continuation with the repeated notes, not a detached feel over the beat, and maybe overall a crescendo feel leading to the
D5 on beat 1.