I asked danmoller this question. He said "Lá" points away from speaker AND listener. "Over there" is best."
But I also have in my notes that "ali" = there (away from the listener and the speaker).
What is the difference between "lá" and "ali"? Are there perhaps regional differences in how Brazilians interpret these words?
Yes, they are interchangeable. But I'd include that lá is farther than ali
Your friend and you arrive at a park to jog and she asks:
- "por onde começamos?"
"por ali" (pointing at the start :-])
"por onde começamos?"
- "por lá" (pointing to a more distant place).
Could this be a response to someone asking how they are getting there? E.g. "Como eles vão chegar ao restaurante? Eles caminham lá."
To make "they walk there" sound natural it would be better to say "they walk there every day"