Just received this from a listserve I subscribe to.

From: gladney@ILLINOIS.EDU
Subject: walking, going

Dear Russian Speakers,

Here are four scenarios:

1. Ona shla po ulitse.
2. Ona khodila po ulitse.
3. Ona shla po parku.
4. Ona khodil po parku.

Is it clear in each case what is going on?

From: Svetlana Grenier <greniers@GEORGETOWN.EDU>
Subject: Re: walking, going

Yes, it is clear: in "shla" she was "walking down the street", "walking
through the park"; in "khodila", she was "walking back and forth in the
street" or "he was walking around in the park." Of course, if you add
other words (say "chasto khodila") it would mean something different.
At least, that's how it sounds to me!

From: "Paul B. Gallagher" <paulbg@PBG-TRANSLATIONS.COM>
Subject: Re: walking, going

In every case, there are inherent ambiguities that the reader must fill
in as the context warrants, or leave open if he doesn't care. Is the
motion linear, circuitous, oscillating, etc.? Is the "she" a woman or a
girl? Is the street broad or narrow? Was she walking on the sidewalk or
in the street? Some parks (typically beside streams) are long and narrow
-- was the motion along the length of the park?

So the question can only be answered if Frank will give us a definition
of "clear" that suits his purpose.

From: oothappam <oothappam@EARTHLINK.NET>
Subject: Re: walking, going

It's nice that this appeared on the group list today,as it's precisely what I've been attempting to learn for the past few days.
My book (Live From Russia) states: Used with verbs of motion, the preposition PO + dative means "around" or "along".Idti meaning walking in one direction, and hodit meaning walking in more than one direction, random motion, a round trip, or simply naming the habit of walking.These verbs are imperfective, too, so it has to be more of a past progressive feeling, not absolute past and done with.
So, it seems to me that the sentences mean:

1. Ona shla po ulitse. She was walking in one direction along the street.
2. Ona khodila po ulitse.She was walking around the street, kind of wandering,looking around.
3. Ona shla po parku.She was was walking around the park, in one direction-from one end to the other, once.This sounds like she was at the edge or one side of it, to me.
4. Ona khodila po parku. She was walking around in the park leisurely, with no real purpose.
---
That is my VERY rudimentary understanding so far!
Nola